Alert dialog in Theme.AppCompat.DayNight

When we use Theme.AppCompat.DayNight  on android , we may want to  customise  alert dialog window background , text and buttons color .Just define  a seperate style for alert  dialog in your  style xml like below .

<style name="CustomDialogStyle" parent="Theme.AppCompat.DayNight.Dialog.Alert">

    <!-- buttons -->
    <item name="colorAccent">#00FF00</item>
    <!-- title and text -->
    <item name="android:textColorPrimary">#000000</item>
    <!-- background you can change some other color than white -->
    <item name="android:background">#FFFFFF</item>
     <!-- change if you want below -->
    <item name="android:textColor">@null</item>
    <item name="android:textSize">@null</item>
</style>

and then call it like

AlertDialog dialog =
        new AlertDialog.Builder(this, R.style.CustomDialogStyle)

For style.xml(night) you can define different style like below

<style name="CustomDialogStyle" parent="Theme.AppCompat.DayNight.Dialog.Alert">

    <!-- buttons -->
    <item name="colorAccent">#00FF00</item>
    <!-- title and text -->
    <item name="android:textColorPrimary">#FFFFFF</item>
    <!-- background you can change to some other color than black-->
    <item name="android:background">#000000</item>
     <!-- change if you want below -->
    <item name="android:textColor">@null</item>
    <item name="android:textSize">@null</item>
</style>