app/src/main/res/values-night/themes.xml

<resources xmlns:tools="http://schemas.android.com/tools">
	<!-- Base application theme. -->
	<style name="Theme.FaceDetect" parent="Theme.MaterialComponents.DayNight.NoActionBar">
		<!-- Primary brand color. -->
		<item name="colorPrimary">@color/purple_200</item>
		<item name="colorPrimaryVariant">@color/purple_700</item>
		<item name="colorOnPrimary">@color/black</item>
		<!-- Secondary brand color. -->
		<item name="colorSecondary">@color/teal_200</item>
		<item name="colorSecondaryVariant">@color/teal_200</item>
		<item name="colorOnSecondary">@color/black</item>
		<!-- Status bar color. -->
		<item name="android:statusBarColor">?attr/colorPrimaryVariant</item>
		<!-- Customize your theme here. -->
	</style>
</resources>