examples/hellobaku/android/app/src/main/res/values-v21/styles.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <style name="AppTheme" parent="android:Theme.Material.Light.DarkActionBar">
        <item name="android:colorPrimary">@color/primary_material_dark</item>
    </style>
</resources>