Set window background colors

src/main/res/values/styles.xml

@@ -10,7 +10,7 @@
         <item name="colorPrimaryDark">@color/primary_dark</item>
         <!--<item name="colorAccent">@android:color/holo_purple</item>-->
 
-        <item name="android:windowBackground">@null</item>
+        <item name="android:windowBackground">@android:color/white</item>
         <item name="asDueDateOverdueColor">#ee5555</item>
         <item name="asEditTextBackground">@null</item>
         <item name="windowActionModeOverlay">true</item>
@@ -72,6 +72,7 @@
     <style name="Tasks.Dark">
         <item name="colorPrimary">@android:color/black</item>
         <item name="colorPrimaryDark">@android:color/black</item>
+        <item name="android:windowBackground">@android:color/black</item>
         <item name="drawer_background">@color/drawer_background_dark</item>
         <item name="drawer_background_selected">@color/drawer_background_selected_dark</item>
         <item name="asToolbarSeparator">@android:color/white</item>