diff --git a/app/build.gradle b/app/build.gradle
index f5f8ff9..bdb9ee0 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -10,10 +10,10 @@ android {
     compileSdkVersion 28
     defaultConfig {
         applicationId "org.mosad.seil0.projectlaogai"
-        minSdkVersion 21
+        minSdkVersion 23
         targetSdkVersion 28
-        versionCode 13
-        versionName "0.4.90"
+        versionCode 14
+        versionName "0.4.91"
         testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
         resValue "string", "build_time", buildTime()
         setProperty("archivesBaseName", "projectlaogai-$versionName")
@@ -37,7 +37,7 @@ dependencies {
     implementation 'org.jetbrains.anko:anko-commons:0.10.8'
     implementation 'androidx.appcompat:appcompat:1.0.2'
     implementation 'androidx.legacy:legacy-support-v4:1.0.0'
-    implementation 'androidx.constraintlayout:constraintlayout:2.0.0-beta1'
+    implementation 'androidx.constraintlayout:constraintlayout:2.0.0-beta2'
     implementation 'androidx.swiperefreshlayout:swiperefreshlayout:1.0.0'
     implementation 'com.google.android.material:material:1.0.0'
     implementation 'com.google.code.gson:gson:2.8.5'
diff --git a/app/src/main/java/org/mosad/seil0/projectlaogai/MainActivity.kt b/app/src/main/java/org/mosad/seil0/projectlaogai/MainActivity.kt
index 6741da6..e0ad511 100644
--- a/app/src/main/java/org/mosad/seil0/projectlaogai/MainActivity.kt
+++ b/app/src/main/java/org/mosad/seil0/projectlaogai/MainActivity.kt
@@ -61,26 +61,7 @@ class MainActivity : AppCompatActivity(), NavigationView.OnNavigationItemSelecte
 
         // load mensa, timetable and color
         load()
-
-        // If we haven't set any defaults, do that now
-        if (Aesthetic.isFirstTime) {
-            // this is executed on the first app start, use this to show tutorial etc.
-            Aesthetic.config {
-                colorPrimary(Color.BLACK)
-                colorPrimaryDark(Color.BLACK)
-                colorAccent(Color.parseColor("#3F51B5"))
-                apply()
-            }
-
-            SettingsFragment().selectCourse(this)
-        } else {
-            Aesthetic.config {
-                colorPrimary(cColorPrimary)
-                colorPrimaryDark(cColorPrimary)
-                colorAccent(cColorAccent)
-                apply()
-            }
-        }
+        initAesthetic()
 
         //init home fragment
         val fragmentTransaction: FragmentTransaction = supportFragmentManager.beginTransaction()
@@ -146,6 +127,7 @@ class MainActivity : AppCompatActivity(), NavigationView.OnNavigationItemSelecte
         fragmentTransaction.commit()
 
         drawer_layout.closeDrawer(GravityCompat.START)
+
         return true
     }
 
@@ -208,4 +190,28 @@ class MainActivity : AppCompatActivity(), NavigationView.OnNavigationItemSelecte
         println("startup completed in $startupTime ms")
     }
 
+    private fun initAesthetic() {
+        // If we haven't set any defaults, do that now
+        if (Aesthetic.isFirstTime) {
+            // this is executed on the first app start, use this to show tutorial etc.
+            Aesthetic.config {
+                activityTheme(R.style.AppTheme)
+                colorPrimary(Color.BLACK)
+                colorPrimaryDark(Color.BLACK)
+                colorAccent(Color.parseColor("#3f51b5"))
+                apply()
+            }
+
+            SettingsFragment().selectCourse(this)
+        } else {
+            Aesthetic.config {
+//                activityTheme(R.style.AppTheme_Light)
+                colorPrimary(cColorPrimary)
+                colorPrimaryDark(cColorPrimary)
+                colorAccent(cColorAccent)
+                apply()
+            }
+        }
+    }
+
 }
diff --git a/app/src/main/java/org/mosad/seil0/projectlaogai/controller/CacheController.kt b/app/src/main/java/org/mosad/seil0/projectlaogai/controller/CacheController.kt
index 2bed4e2..109e8a4 100644
--- a/app/src/main/java/org/mosad/seil0/projectlaogai/controller/CacheController.kt
+++ b/app/src/main/java/org/mosad/seil0/projectlaogai/controller/CacheController.kt
@@ -37,6 +37,10 @@ class CacheController(cont: Context) {
 
     private val context = cont
 
+    init {
+        // TODO move cache check here
+    }
+
     companion object {
         var coursesList = ArrayList<Course>()
         var timetables = ArrayList<TimetableWeek>()
diff --git a/app/src/main/java/org/mosad/seil0/projectlaogai/fragments/HomeFragment.kt b/app/src/main/java/org/mosad/seil0/projectlaogai/fragments/HomeFragment.kt
index e8b2212..68ad76f 100644
--- a/app/src/main/java/org/mosad/seil0/projectlaogai/fragments/HomeFragment.kt
+++ b/app/src/main/java/org/mosad/seil0/projectlaogai/fragments/HomeFragment.kt
@@ -60,7 +60,7 @@ class HomeFragment : Fragment() {
         val view: View = inflater.inflate(R.layout.fragment_home, container, false)
 
         addMensaMenu().get()
-        addTimeTable()
+        addTimeTable().get()
 
         // Inflate the layout for this fragment
         return view
@@ -75,42 +75,48 @@ class HomeFragment : Fragment() {
         val cal = Calendar.getInstance()
         val mensaCardView = DayCardView(context!!)
 
+
+
         uiThread {
 
-            if (cal.get(Calendar.HOUR_OF_DAY) < 15) {
-                dayMeals = mensaMenu.currentWeek.days[NotRetardedCalendar().getDayOfWeekIndex()].meals
-                mensaCardView.setDayHeading(resources.getString(R.string.today_date, formatter.format(cal.time)))
-            } else {
-                dayMeals = mensaMenu.currentWeek.days[NotRetardedCalendar().getTomorrowWeekIndex()].meals
-                cal.add(Calendar.DATE, 1)
-                mensaCardView.setDayHeading(resources.getString(R.string.tomorrow_date, formatter.format(cal.time)))
-            }
-
-            if (dayMeals.size >= 2) {
-                // get the index of the first meal, not a "Schneller Teller"
-                loop@ for ((i, meal) in dayMeals.withIndex()) {
-                    if (meal.heading.contains("Essen")) {
-
-                        val meal1Layout = MealLinearLayout(context)
-                        meal1Layout.setMeal(dayMeals[i])
-                        mensaCardView.getLinLayoutDay().addView(meal1Layout)
-
-                        val meal2Layout = MealLinearLayout(context)
-                        meal2Layout.setMeal(dayMeals[i + 1])
-                        meal2Layout.disableDivider()
-                        mensaCardView.getLinLayoutDay().addView(meal2Layout)
-
-                        break@loop
-                    }
+            if (isAdded) {
+                if (cal.get(Calendar.HOUR_OF_DAY) < 15) {
+                    dayMeals = mensaMenu.currentWeek.days[NotRetardedCalendar().getDayOfWeekIndex()].meals
+                    mensaCardView.setDayHeading(activity!!.resources.getString(R.string.today_date, formatter.format(cal.time)))
+                } else {
+                    dayMeals = mensaMenu.currentWeek.days[NotRetardedCalendar().getTomorrowWeekIndex()].meals
+                    cal.add(Calendar.DATE, 1)
+                    mensaCardView.setDayHeading(activity!!.resources.getString(R.string.tomorrow_date, formatter.format(cal.time)))
                 }
 
-            } else {
-                mensaCardView.getLinLayoutDay().addView(getNoCard(resources.getString(R.string.mensa_closed)))
+                if (dayMeals.size >= 2) {
+                    // get the index of the first meal, not a "Schneller Teller"
+                    loop@ for ((i, meal) in dayMeals.withIndex()) {
+                        if (meal.heading.contains("Essen")) {
+
+                            val meal1Layout = MealLinearLayout(context)
+                            meal1Layout.setMeal(dayMeals[i])
+                            mensaCardView.getLinLayoutDay().addView(meal1Layout)
+
+                            val meal2Layout = MealLinearLayout(context)
+                            meal2Layout.setMeal(dayMeals[i + 1])
+                            meal2Layout.disableDivider()
+                            mensaCardView.getLinLayoutDay().addView(meal2Layout)
+
+                            break@loop
+                        }
+                    }
+
+                } else {
+                    mensaCardView.getLinLayoutDay().addView(getNoCard(resources.getString(R.string.mensa_closed)))
+                }
+
+                linLayout_Home.addView(mensaCardView)
             }
 
-            linLayout_Home.addView(mensaCardView)
         }
 
+
     }
 
     /**
@@ -123,29 +129,30 @@ class HomeFragment : Fragment() {
 
         uiThread {
 
-            if (timetables.isNotEmpty() && dayIndex < 6) {
+            if (isAdded) {
+                if (timetables.isNotEmpty() && dayIndex < 6) {
 
-                // first check the current day
-                dayCardView = addDayTimetable(timetables[0].days[dayIndex])
-                dayCardView.setDayHeading(resources.getString(R.string.today_date, formatter.format(cal.time)))
+                    // first check the current day
+                    dayCardView = addDayTimetable(timetables[0].days[dayIndex])
+                    dayCardView.setDayHeading(resources.getString(R.string.today_date, formatter.format(cal.time)))
 
-                // if there are no lessons try to find the next day with a lesson
-                if (dayCardView.getLinLayoutDay().childCount <= 1)
-                    dayCardView = findNextDay(0, dayIndex + 1)
+                    // if there are no lessons try to find the next day with a lesson
+                    if (dayCardView.getLinLayoutDay().childCount <= 1)
+                        dayCardView = findNextDay(0, dayIndex + 1)
 
-                linLayout_Home.addView(dayCardView)
-            } else if (dayIndex == 6) {
-                // if that's the case it's sunday
-                dayCardView = findNextDay(1, 0)
-                linLayout_Home.addView(dayCardView)
-            } else {
-                MaterialDialog(context!!)
-                    .title(R.string.error)
-                    .message(R.string.timetable_error)
-                    .show()
-                // TODO log the error and send feedback
+                    linLayout_Home.addView(dayCardView)
+                } else if (dayIndex == 6) {
+                    // if that's the case it's sunday
+                    dayCardView = findNextDay(1, 0)
+                    linLayout_Home.addView(dayCardView)
+                } else {
+                    MaterialDialog(context!!)
+                        .title(R.string.error)
+                        .message(R.string.timetable_error)
+                        .show()
+                    // TODO log the error and send feedback
+                }
             }
-
         }
 
     }
diff --git a/app/src/main/java/org/mosad/seil0/projectlaogai/fragments/SettingsFragment.kt b/app/src/main/java/org/mosad/seil0/projectlaogai/fragments/SettingsFragment.kt
index 972e243..365e87b 100644
--- a/app/src/main/java/org/mosad/seil0/projectlaogai/fragments/SettingsFragment.kt
+++ b/app/src/main/java/org/mosad/seil0/projectlaogai/fragments/SettingsFragment.kt
@@ -50,6 +50,7 @@ import org.mosad.seil0.projectlaogai.controller.CacheController.Companion.course
 import org.mosad.seil0.projectlaogai.controller.TCoRAPIController
 import org.mosad.seil0.projectlaogai.hsoparser.DataTypes
 import java.util.*
+import android.util.TypedValue
 
 /**
  * The settings controller class
@@ -87,6 +88,14 @@ class SettingsFragment : Fragment() {
         txtView_Course.text = cCourse.courseName
         txtView_AboutDesc.text =  resources.getString(R.string.about_version, BuildConfig.VERSION_NAME, getString(R.string.build_time))
         switch_buffet.isChecked = cShowBuffet // init switch
+
+        val outValue = TypedValue()
+        activity!!.theme.resolveAttribute(R.attr.themeName, outValue, true)
+        if (outValue.string == "dark") {
+            switch_buffet.setTextColor(activity!!.resources.getColor(R.color.textPrimaryDark, activity!!.theme))
+        } else {
+            switch_buffet.setTextColor(activity!!.resources.getColor(R.color.textPrimaryLight, activity!!.theme))
+        }
     }
 
     /**
@@ -95,6 +104,19 @@ class SettingsFragment : Fragment() {
     private fun initActions() {
         linLayoutUser.setOnClickListener {
             // open a new dialog
+            // TODO move and save
+//            val outValue = TypedValue()
+//            activity!!.theme.resolveAttribute(R.attr.themeName, outValue, true)
+//            if (outValue.string == "dark") {
+//                Aesthetic.config {
+//                    activityTheme(R.style.AppTheme_Light)
+//                }
+//            } else {
+//                Aesthetic.config {
+//                    activityTheme(R.style.AppTheme_Dark)
+//                }
+//            }
+
         }
 
         linLayoutCourse.setOnClickListener {
diff --git a/app/src/main/java/org/mosad/seil0/projectlaogai/fragments/TimeTableFragment.kt b/app/src/main/java/org/mosad/seil0/projectlaogai/fragments/TimeTableFragment.kt
index 5fdd17b..90482dd 100644
--- a/app/src/main/java/org/mosad/seil0/projectlaogai/fragments/TimeTableFragment.kt
+++ b/app/src/main/java/org/mosad/seil0/projectlaogai/fragments/TimeTableFragment.kt
@@ -22,7 +22,6 @@
 
 package org.mosad.seil0.projectlaogai.fragments
 
-import android.os.Build
 import android.os.Bundle
 import android.view.LayoutInflater
 import android.view.View
@@ -94,17 +93,15 @@ class TimeTableFragment : Fragment() {
                     .show()
             }
 
-            // TODO only works with android m(23) or higher
             // hide the btnCardValue if the user is scrolling down
-            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
-                scrollViewTimetable.setOnScrollChangeListener { v, scrollX, scrollY, oldScrollX, oldScrollY ->
-                    if (scrollY > oldScrollY) {
-                        faBtnAddLesson.hide()
-                    } else {
-                        faBtnAddLesson.show()
-                    }
+            scrollViewTimetable.setOnScrollChangeListener { v, scrollX, scrollY, oldScrollX, oldScrollY ->
+                if (scrollY > oldScrollY) {
+                    faBtnAddLesson.hide()
+                } else {
+                    faBtnAddLesson.show()
                 }
             }
+
         }
 
     }
diff --git a/app/src/main/res/drawable/background_splash.xml b/app/src/main/res/drawable/background_splash.xml
index f9df9fc..9de6881 100644
--- a/app/src/main/res/drawable/background_splash.xml
+++ b/app/src/main/res/drawable/background_splash.xml
@@ -3,9 +3,7 @@
 
     <item android:drawable="@color/colorPrimary"/>
 
-    <!--TODO when minAPI is 23 use this-->
-    <!--<item android:gravity="center" android:width="144dp" android:height="144dp">-->
-    <item android:gravity="center">
+    <item android:gravity="center" android:width="144dp" android:height="144dp">
         <bitmap
                 android:gravity="fill_horizontal|fill_vertical"
                 android:src="@mipmap/ic_laogai_icon_splash"/>
diff --git a/app/src/main/res/layout/cardview_day.xml b/app/src/main/res/layout/cardview_day.xml
index 8c27625..4ce5d7a 100644
--- a/app/src/main/res/layout/cardview_day.xml
+++ b/app/src/main/res/layout/cardview_day.xml
@@ -3,7 +3,7 @@
                                    xmlns:app="http://schemas.android.com/apk/res-auto"
                                    android:layout_width="match_parent"
                                    android:layout_height="wrap_content" app:cardUseCompatPadding="true"
-                                   app:cardElevation="5dp" app:cardBackgroundColor="@color/themeSecondary"
+                                   app:cardElevation="5dp" app:cardBackgroundColor="?themeSecondary"
 >
 
     <LinearLayout
diff --git a/app/src/main/res/layout/fragment_home.xml b/app/src/main/res/layout/fragment_home.xml
index 7d10427..0971b9c 100644
--- a/app/src/main/res/layout/fragment_home.xml
+++ b/app/src/main/res/layout/fragment_home.xml
@@ -3,7 +3,8 @@
              xmlns:tools="http://schemas.android.com/tools"
              android:layout_width="match_parent"
              android:layout_height="match_parent"
-             tools:context=".fragments.HomeFragment">
+             tools:context=".fragments.HomeFragment"
+             android:background="?themePrimary">
 
     <androidx.constraintlayout.widget.ConstraintLayout
             android:layout_width="match_parent"
diff --git a/app/src/main/res/layout/fragment_mensa.xml b/app/src/main/res/layout/fragment_mensa.xml
index b972be0..692f063 100644
--- a/app/src/main/res/layout/fragment_mensa.xml
+++ b/app/src/main/res/layout/fragment_mensa.xml
@@ -1,9 +1,10 @@
 <?xml version="1.0" encoding="utf-8"?>
 <FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
-             xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools"
+             xmlns:tools="http://schemas.android.com/tools"
              android:layout_width="match_parent"
              android:layout_height="match_parent"
-             tools:context=".fragments.MensaFragment">
+             tools:context=".fragments.MensaFragment"
+             android:background="?themePrimary">
 
     <androidx.swiperefreshlayout.widget.SwipeRefreshLayout
             android:layout_width="match_parent"
@@ -12,13 +13,13 @@
 
         <ScrollView
                 android:layout_width="match_parent"
-                android:layout_height="match_parent" android:id="@+id/scrollView_Mensa">
+                android:layout_height="match_parent"
+                android:id="@+id/scrollView_Mensa">
             <LinearLayout
                     android:orientation="vertical"
                     android:layout_width="match_parent"
                     android:layout_height="wrap_content"
                     android:animateLayoutChanges="false"
-                    android:background="@color/themePrimary"
                     android:id="@+id/linLayout_Mensa"/>
         </ScrollView>
     </androidx.swiperefreshlayout.widget.SwipeRefreshLayout>
diff --git a/app/src/main/res/layout/fragment_settings.xml b/app/src/main/res/layout/fragment_settings.xml
index 6429411..7890591 100644
--- a/app/src/main/res/layout/fragment_settings.xml
+++ b/app/src/main/res/layout/fragment_settings.xml
@@ -1,9 +1,11 @@
 <?xml version="1.0" encoding="utf-8"?>
 <FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
-             xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools"
+             xmlns:app="http://schemas.android.com/apk/res-auto"
+             xmlns:tools="http://schemas.android.com/tools"
              android:layout_width="match_parent"
              android:layout_height="match_parent"
-             tools:context=".fragments.SettingsFragment">
+             tools:context=".fragments.SettingsFragment"
+             android:background="?themePrimary">
 
     <androidx.constraintlayout.widget.ConstraintLayout
             android:layout_width="match_parent"
@@ -12,14 +14,19 @@
         <LinearLayout
                 android:orientation="vertical"
                 android:layout_width="match_parent"
-                android:layout_height="match_parent" app:layout_constraintTop_toTopOf="parent"
-                app:layout_constraintStart_toStartOf="parent" app:layout_constraintEnd_toEndOf="parent"
-                android:background="@android:color/background_light">
+                android:layout_height="match_parent"
+                app:layout_constraintTop_toTopOf="parent"
+                app:layout_constraintStart_toStartOf="parent"
+                app:layout_constraintEnd_toEndOf="parent"
+        >
             <androidx.cardview.widget.CardView
                     android:layout_width="match_parent"
                     android:layout_height="wrap_content"
-                    android:layout_marginTop="9dp" android:id="@+id/cardView_Info" app:cardElevation="5dp"
-                    app:cardUseCompatPadding="true">
+                    android:layout_marginTop="9dp"
+                    android:id="@+id/cardView_Info"
+                    app:cardElevation="5dp"
+                    app:cardUseCompatPadding="true"
+                    app:cardBackgroundColor="?themeSecondary">
                 <LinearLayout
                         android:orientation="vertical"
                         android:layout_width="match_parent"
@@ -27,24 +34,33 @@
                     <TextView
                             android:text="@string/info"
                             android:layout_width="match_parent"
-                            android:layout_height="wrap_content" android:id="@+id/txtView_Info"
+                            android:layout_height="wrap_content"
+                            android:id="@+id/txtView_Info"
                             android:typeface="sans"
-                            android:textSize="18sp" android:textStyle="bold" android:fontFamily="sans-serif"
-                            android:layout_margin="7dp" android:textColor="?colorAccent"/>
+                            android:textSize="18sp"
+                            android:textStyle="bold"
+                            android:fontFamily="sans-serif"
+                            android:layout_margin="7dp"
+                            android:textColor="?colorAccent"/>
                     <LinearLayout
                             android:orientation="vertical"
                             android:layout_width="match_parent"
-                            android:layout_height="wrap_content" android:padding="7dp" android:id="@+id/linLayout_User">
+                            android:layout_height="wrap_content"
+                            android:padding="7dp"
+                            android:id="@+id/linLayout_User">
                         <TextView
                                 android:text="@string/sample_user"
                                 android:layout_width="match_parent"
-                                android:layout_height="wrap_content" android:id="@+id/txtView_User"
-                                android:textSize="16sp" android:textStyle="bold"
-                                android:textColor="@android:color/primary_text_light"/>
+                                android:layout_height="wrap_content"
+                                android:id="@+id/txtView_User"
+                                android:textSize="16sp"
+                                android:textStyle="bold"
+                        />
                         <TextView
                                 android:text="@string/user"
                                 android:layout_width="match_parent"
-                                android:layout_height="wrap_content" android:id="@+id/txtView_UserDesc"/>
+                                android:layout_height="wrap_content"
+                                android:id="@+id/txtView_UserDesc"/>
                     </LinearLayout>
                     <View
                             android:id="@+id/divider2"
@@ -55,18 +71,21 @@
                     <LinearLayout
                             android:orientation="vertical"
                             android:layout_width="match_parent"
-                            android:layout_height="wrap_content" android:layout_margin="7dp"
+                            android:layout_height="wrap_content"
+                            android:layout_margin="7dp"
                             android:id="@+id/linLayout_Course">
                         <TextView
                                 android:text="@string/sample_course"
                                 android:layout_width="match_parent"
-                                android:layout_height="wrap_content" android:id="@+id/txtView_Course"
-                                android:textSize="16sp" android:textColor="@android:color/primary_text_light"
+                                android:layout_height="wrap_content"
+                                android:id="@+id/txtView_Course"
+                                android:textSize="16sp"
                                 android:textStyle="bold"/>
                         <TextView
                                 android:text="@string/course_desc"
                                 android:layout_width="match_parent"
-                                android:layout_height="wrap_content" android:id="@+id/txtView_CourseDesc"/>
+                                android:layout_height="wrap_content"
+                                android:id="@+id/txtView_CourseDesc"/>
                     </LinearLayout>
                     <View
                             android:id="@+id/divider"
@@ -77,43 +96,57 @@
                     <LinearLayout
                             android:orientation="vertical"
                             android:layout_width="match_parent"
-                            android:layout_height="match_parent" android:layout_margin="7dp"
+                            android:layout_height="match_parent"
+                            android:layout_margin="7dp"
                             android:id="@+id/linLayout_About">
                         <TextView
                                 android:text="@string/about_txtView"
                                 android:layout_width="match_parent"
-                                android:layout_height="wrap_content" android:id="@+id/txtView_About"
-                                android:textStyle="bold" android:textSize="16sp"
-                                android:textColor="@android:color/primary_text_light"/>
+                                android:layout_height="wrap_content"
+                                android:id="@+id/txtView_About"
+                                android:textStyle="bold"
+                                android:textSize="16sp"
+                        />
                         <TextView
                                 android:text="@string/about_version"
                                 android:layout_width="match_parent"
-                                android:layout_height="wrap_content" android:id="@+id/txtView_AboutDesc"/>
+                                android:layout_height="wrap_content"
+                                android:id="@+id/txtView_AboutDesc"/>
                     </LinearLayout>
                 </LinearLayout>
             </androidx.cardview.widget.CardView>
+
             <androidx.cardview.widget.CardView
                     android:layout_width="match_parent"
                     android:layout_height="wrap_content"
-                    android:id="@+id/cardView_Settings" app:cardElevation="5dp"
-                    app:cardUseCompatPadding="true">
+                    android:id="@+id/cardView_Settings"
+                    app:cardElevation="5dp"
+                    app:cardUseCompatPadding="true"
+                    app:cardBackgroundColor="?themeSecondary">
                 <LinearLayout
                         android:orientation="vertical"
                         android:layout_width="match_parent"
-                        android:layout_height="wrap_content" android:id="@+id/linLayout_Settings" android:padding="7dp">
+                        android:layout_height="wrap_content"
+                        android:id="@+id/linLayout_Settings"
+                        android:padding="7dp">
                     <TextView
                             android:text="@string/settings"
                             android:layout_width="match_parent"
-                            android:layout_height="wrap_content" android:id="@+id/txtView_Settings"
+                            android:layout_height="wrap_content"
+                            android:id="@+id/txtView_Settings"
                             android:typeface="sans"
-                            android:textSize="18sp" android:textColor="?colorAccent"
-                            android:textStyle="bold" android:paddingTop="3dp"/>
+                            android:textSize="18sp"
+                            android:textColor="?colorAccent"
+                            android:textStyle="bold"
+                            android:paddingTop="3dp"/>
                     <LinearLayout
                             android:orientation="horizontal"
                             android:layout_width="match_parent"
                             android:layout_height="wrap_content"
                             android:gravity="center_vertical|end"
-                            android:clickable="true" android:id="@+id/linLayout_PrimaryColor" android:focusable="true">
+                            android:clickable="true"
+                            android:id="@+id/linLayout_PrimaryColor"
+                            android:focusable="true">
                         <LinearLayout
                                 android:orientation="vertical"
                                 android:layout_width="wrap_content"
@@ -121,22 +154,27 @@
                             <TextView
                                     android:text="@string/primary_color"
                                     android:layout_width="match_parent"
-                                    android:layout_height="wrap_content" android:id="@+id/txtView_PrimaryColor"
-                                    android:textSize="16sp" android:textStyle="bold"
-                                    android:textColor="@android:color/primary_text_light"/>
+                                    android:layout_height="wrap_content"
+                                    android:id="@+id/txtView_PrimaryColor"
+                                    android:textSize="16sp"
+                                    android:textStyle="bold"
+                            />
                             <TextView
                                     android:text="@string/primary_color_desc"
                                     android:layout_width="match_parent"
-                                    android:layout_height="wrap_content" android:id="@+id/txtView_PrimaryColorDesc"/>
+                                    android:layout_height="wrap_content"
+                                    android:id="@+id/txtView_PrimaryColorDesc"/>
                         </LinearLayout>
                         <LinearLayout
                                 android:orientation="vertical"
                                 android:layout_width="match_parent"
-                                android:layout_height="wrap_content" android:layout_margin="7dp"
+                                android:layout_height="wrap_content"
+                                android:layout_margin="7dp"
                                 android:gravity="end">
                             <View
                                     android:layout_width="40dp"
-                                    android:layout_height="40dp" android:id="@+id/view_PrimaryColor"
+                                    android:layout_height="40dp"
+                                    android:id="@+id/view_PrimaryColor"
                                     android:background="?colorPrimary"/>
                         </LinearLayout>
                     </LinearLayout>
@@ -145,7 +183,9 @@
                             android:layout_width="match_parent"
                             android:layout_height="wrap_content"
                             android:gravity="center_vertical|end"
-                            android:clickable="true" android:id="@+id/linLayout_AccentColor" android:focusable="true">
+                            android:clickable="true"
+                            android:id="@+id/linLayout_AccentColor"
+                            android:focusable="true">
                         <LinearLayout
                                 android:orientation="vertical"
                                 android:layout_width="wrap_content"
@@ -153,31 +193,38 @@
                             <TextView
                                     android:text="@string/accent_color"
                                     android:layout_width="match_parent"
-                                    android:layout_height="wrap_content" android:id="@+id/txtView_AccentColor"
-                                    android:textSize="16sp" android:textStyle="bold"
-                                    android:textColor="@android:color/primary_text_light"/>
+                                    android:layout_height="wrap_content"
+                                    android:id="@+id/txtView_AccentColor"
+                                    android:textSize="16sp"
+                                    android:textStyle="bold"
+                            />
                             <TextView
                                     android:text="@string/accent_color_desc"
                                     android:layout_width="match_parent"
-                                    android:layout_height="wrap_content" android:id="@+id/txtView_AccentColorDesc"/>
+                                    android:layout_height="wrap_content"
+                                    android:id="@+id/txtView_AccentColorDesc"/>
                         </LinearLayout>
                         <LinearLayout
                                 android:orientation="vertical"
                                 android:layout_width="match_parent"
-                                android:layout_height="wrap_content" android:layout_margin="7dp"
+                                android:layout_height="wrap_content"
+                                android:layout_margin="7dp"
                                 android:gravity="end">
                             <View
                                     android:layout_width="40dp"
-                                    android:layout_height="40dp" android:id="@+id/view_AccentColor"
+                                    android:layout_height="40dp"
+                                    android:id="@+id/view_AccentColor"
                                     android:background="?colorAccent"/>
                         </LinearLayout>
                     </LinearLayout>
                     <Switch
                             android:layout_width="match_parent"
-                            android:layout_height="wrap_content" android:id="@+id/switch_buffet"
+                            android:layout_height="wrap_content"
+                            android:id="@+id/switch_buffet"
                             android:textSize="16sp"
-                            android:textColor="@android:color/primary_text_light" android:textStyle="bold"
-                            android:text="@string/show_buffet"/>
+                            android:textStyle="bold"
+                            android:text="@string/show_buffet"
+                    />
                 </LinearLayout>
             </androidx.cardview.widget.CardView>
         </LinearLayout>
diff --git a/app/src/main/res/layout/fragment_timetable.xml b/app/src/main/res/layout/fragment_timetable.xml
index ea2f788..812720e 100644
--- a/app/src/main/res/layout/fragment_timetable.xml
+++ b/app/src/main/res/layout/fragment_timetable.xml
@@ -1,9 +1,10 @@
 <?xml version="1.0" encoding="utf-8"?>
 <FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
-             xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools"
+             xmlns:tools="http://schemas.android.com/tools"
              android:layout_width="match_parent"
              android:layout_height="match_parent"
-             tools:context=".fragments.TimeTableFragment">
+             tools:context=".fragments.TimeTableFragment"
+             android:background="?themePrimary">
 
     <androidx.swiperefreshlayout.widget.SwipeRefreshLayout
             android:layout_width="match_parent"
@@ -18,7 +19,6 @@
                     android:layout_width="match_parent"
                     android:layout_height="wrap_content"
                     android:animateLayoutChanges="false"
-                    android:background="@color/themePrimary"
                     android:id="@+id/linLayout_Timetable"/>
         </ScrollView>
     </androidx.swiperefreshlayout.widget.SwipeRefreshLayout>
diff --git a/app/src/main/res/layout/linearlayout_lesson.xml b/app/src/main/res/layout/linearlayout_lesson.xml
index 4012441..d51021a 100644
--- a/app/src/main/res/layout/linearlayout_lesson.xml
+++ b/app/src/main/res/layout/linearlayout_lesson.xml
@@ -11,7 +11,7 @@
         <TextView
                 android:layout_width="wrap_content"
                 android:layout_height="wrap_content" android:id="@+id/txtView_lessonSubject" android:layout_weight="1"
-                android:textSize="15sp" android:textColor="@color/textPrimary"/>
+                android:textSize="15sp"/>
         <TextView
                 android:text="@string/a_time"
                 android:layout_width="wrap_content"
@@ -21,15 +21,15 @@
     <TextView
             android:layout_width="match_parent"
             android:layout_height="wrap_content" android:id="@+id/txtView_lessonTeacher" android:textSize="15sp"
-            android:textColor="@color/textPrimary"/>
+    />
     <TextView
             android:layout_width="match_parent"
             android:layout_height="wrap_content" android:id="@+id/txtView_lessonRoom"
-            android:textColor="@color/textPrimary"/>
+    />
     <View
             android:id="@+id/divider_lesson"
             android:layout_width="match_parent"
             android:layout_height="1dp"
-            android:background="?android:attr/listDivider"
+            android:background="?dividerColor"
     />
 </LinearLayout>
\ No newline at end of file
diff --git a/app/src/main/res/layout/linearlayout_meal.xml b/app/src/main/res/layout/linearlayout_meal.xml
index 15752aa..61d7a32 100644
--- a/app/src/main/res/layout/linearlayout_meal.xml
+++ b/app/src/main/res/layout/linearlayout_meal.xml
@@ -8,16 +8,16 @@
             android:text="@string/meal"
             android:layout_width="match_parent"
             android:layout_height="wrap_content" android:id="@+id/txtView_MealHeading" android:textSize="18sp"
-            android:textColor="@color/textPrimary" android:textAlignment="center" android:paddingBottom="5dp"
+            android:textAlignment="center" android:paddingBottom="5dp"
             android:textStyle="bold"/>
     <TextView
             android:layout_width="match_parent"
             android:layout_height="wrap_content" android:id="@+id/txtView_Meal" android:textSize="15sp"
-            android:textColor="@color/textPrimary" android:textAlignment="center"/>
+            android:textAlignment="center"/>
     <View
             android:id="@+id/divider_meal"
             android:layout_width="match_parent"
             android:layout_height="1dp"
-            android:background="?android:attr/listDivider"
+            android:background="?dividerColor"
     />
 </LinearLayout>
\ No newline at end of file
diff --git a/app/src/main/res/values/attrs.xml b/app/src/main/res/values/attrs.xml
new file mode 100644
index 0000000..da9cee6
--- /dev/null
+++ b/app/src/main/res/values/attrs.xml
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+    <attr format="string" name="themeName"/>
+    <attr format="color" name="themePrimary"/>
+    <attr format="color" name="themeSecondary"/>
+    <attr format="color" name="textPrimary"/>
+    <attr format="color" name="textSecondary"/>
+    <attr format="color" name="dividerColor"/>
+</resources>
\ No newline at end of file
diff --git a/app/src/main/res/values/colors.xml b/app/src/main/res/values/colors.xml
index 7f52220..92bab79 100644
--- a/app/src/main/res/values/colors.xml
+++ b/app/src/main/res/values/colors.xml
@@ -2,28 +2,27 @@
 <resources>
     <color name="colorPrimary">#000000</color>
     <color name="colorPrimaryDark">#000000</color>
-    <color name="colorAccent">#3F51B5</color>
-    <color name="ic_launcher_background">#FFFFFF</color>
-
-    <color name="themePrimary">#FFFFFF</color>
-    <color name="themeSecondary">#FFFFFF</color>
-    <color name="themeTertiary">#FAFAFA</color> <!-- TODO find a better color -->
+    <color name="colorAccent">#3f51b5</color>
+    <color name="ic_launcher_background">#ffffff</color>
 
+    <color name="themePrimary">#ffffff</color>
+    <color name="themeSecondary">#ffffff</color>
     <color name="textPrimary">#000000</color>
     <color name="textSecondary">#818181</color>
 
     <!--theme color section, not the working colors-->
-    <color name="textPrimaryDark">#FFFFFF</color>
-    <color name="textSecondaryDark">#E0E0E0</color>
-    <color name="textPrimaryLight">#000000</color>
-    <color name="textSecondaryLight">#818181</color>
-
     <color name="themePrimaryDark">#000000</color>
     <color name="themeSecondaryDark">#303030</color>
     <color name="themeTertiaryDark">#424242</color>
+    <color name="textPrimaryDark">#ffffff</color>
+    <color name="textSecondaryDark">#e0e0e0</color>
+    <color name="dividerDark">#232323</color>
+
+    <color name="themePrimaryLight">#ffffff</color>
+    <color name="themeSecondaryLight">#ffffff</color>
+    <color name="textPrimaryLight">#000000</color>
+    <color name="textSecondaryLight">#818181</color>
+    <color name="dividerLight">#e0e0e0</color>
 
-    <color name="themePrimaryLight">#FFFFFF</color>
-    <color name="themeSecondaryLight">#FFFFFF</color>
-    <color name="themeTertiaryLight">#424242</color> <!-- TODO find a better color -->
 
 </resources>
diff --git a/app/src/main/res/values/styles.xml b/app/src/main/res/values/styles.xml
index a27a731..1bd2b68 100644
--- a/app/src/main/res/values/styles.xml
+++ b/app/src/main/res/values/styles.xml
@@ -1,13 +1,30 @@
 <resources>
 
     <!-- Base application theme. -->
-    <style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
-        <!-- Customize your theme here. -->
+    <style name="AppTheme" parent="Theme.AppCompat.Light.NoActionBar">
         <item name="colorPrimary">@color/colorPrimary</item>
         <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
         <item name="colorAccent">@color/colorAccent</item>
     </style>
 
+    <style name="AppTheme.Light" parent="AppTheme">
+        <item name="themeName">light</item>
+        <item name="themePrimary">@color/themePrimaryLight</item>
+        <item name="themeSecondary">@color/themeSecondaryLight</item>
+        <item name="android:textColor">@color/textPrimaryLight</item>
+        <item name="textPrimary">@color/textPrimaryLight</item>
+        <item name="dividerColor">@color/dividerLight</item>
+    </style>
+
+    <style name="AppTheme.Dark" parent="AppTheme">
+        <item name="themeName">dark</item>
+        <item name="themePrimary">@color/themePrimaryDark</item>
+        <item name="themeSecondary">@color/themeSecondaryDark</item>
+        <item name="android:textColor">@color/textPrimaryDark</item>
+        <item name="textPrimary">@color/textPrimaryDark</item>
+        <item name="dividerColor">@color/dividerDark</item>
+    </style>
+
     <style name="AppTheme.NoActionBar">
         <item name="windowActionBar">false</item>
         <item name="windowNoTitle">true</item>