<?xml version="1.0" encoding="utf-8"?>
<resources>

    <!-- Base application theme. -->
    <style name="AppTheme.DayNight" parent="Theme.AppCompat.DayNight">
        <!-- Customize your theme here. -->
        <item name="colorPrimary">@color/colorPrimary</item>
        <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
        <item name="colorAccent">@color/colorAccent</item>
        <item name="android:windowBackground">@color/windowBackground</item>

    </style>

    <style name="AppTheme.DayNight.NoActionBar">
        <item name="windowActionBar">false</item>
        <item name="windowNoTitle">true</item>
    </style>

    <style name="AppTheme.AppBarOverlay" parent="ThemeOverlay.AppCompat.Dark.ActionBar">
        <item name="android:textColorPrimary">@color/colorTextPrimary</item>
        <item name="android:textColorSecondary">@color/colorTextSecondary</item>
        <item name="android:textColorTertiary">@color/colorTextTertiary</item>
    </style>
</resources>
Implement a night theme XML
Implement a night theme XML
