How can I remove the Android black screen at load-after preview, before splash screen

There is a black screen appearing at App Launch on Android, after the Android Preview image and before Unity splash screen. I couldn't find an Unity app that has a different (non-black) start color screen so far. The order of appearing (resulting in an ugly flash) android theme color preview unknown black screen unity splash screen our scene

Android 5.1.1, 6.0.1 (and more) Built with Unity 5.3.4.f1 Empty project with Android theme set as any color and a custom unity splash screen image/color.

1. Example custom android manifest

   < resources> < color name="xx_custom_theme_color">#b0b0ff < /color> < style name="xxCustomStyle" parent="@android:style/Theme.NoTitleBar.Fullscreen"> < item name="android:windowBackground">@color/xx_custom_theme_color< /item> < item name="android:colorBackground">@color/xx_custom_theme_color< /item> < !-- @drawable/notification_badge< /item> --> < !-- true< /item> --> < /style> < /resources>

Has anyone made an app/game with a non-black start screen?