Changing the background Color of the Popup-/Overflow-Menu on Android?

Hey together, has anyone already changed the Background Color of the Android PopupMenu in a Xamarin.Forms app?

The following code in the Styles.xml should but has not worked for me:

<style name="AppTheme" parent="android:Theme.Material.Light">
    <item name="android:popupMenuStyle">\@style/PopupMenu</item>
</style>
<style name="PopupMenu" parent="@android:style/Widget.Material.Light.ListPopupWindow">
    <item name="android:popupBackground">@android:color/popup_background_color</item>
</style>

Also the following approaches weren't successful so far:
- PopupMenu instead of ListPopupWindow as the style's parent
- android:styleinstead of _@android:style/

Do you have any ideas? Thanks in advance!