wireguard-android/app/src/main/res/values/styles.xml

<?xml version="1.0" encoding="utf-8"?>
<resources xmlns:android="http://schemas.android.com/apk/res/android">

    <style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar" />
    <style name="SettingsTheme" parent="AppTheme">
        <item name="preferenceTheme">@style/PreferenceThemeOverlay.v14.Material</item>
    </style>
    <style name="fab_label" parent="android:TextAppearance.DeviceDefault.Inverse">
        <item name="android:background">@drawable/fab_label_background</item>
    </style>

</resources>