I ended up using the following layerlist
as the drawable
for the actionbar background
:
<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
<item android:drawable="@color/brand_orange" />
<item android:drawable="@color/brand_purple" android:bottom="2dp" />
</layer-list>
All suggestions welcome for another approach using 9-patch.