android-calculatorpp/calculatorpp/res/values/theme_metro_purple.xml

<resources>

	<style name="metro_purple_operation_button_style" parent="metro_digit_button_style">
		<item name="android:background">@drawable/metro_button_purple</item>
	</style>


    <style name="metro_purple_fragment_list_view_item_style" parent="default_fragment_list_view_item_style">
        <item name="background">@drawable/metro_purple_list_item</item>
        <item name="android:background">@drawable/metro_purple_list_item</item>
    </style>

	<style name="metro_purple_theme" parent="metro_blue_theme">
		<item name="cpp_operation_button_style">@style/metro_purple_operation_button_style</item>
        <item name="cpp_fragment_list_view_item_style">@style/metro_purple_fragment_list_view_item_style</item>
    </style>

</resources>