styles.xml

<resources>

    <style name="AppTheme" parent="Theme.AppCompat.Light.NoActionBar">
        <item name="colorPrimary">@color/colorPrimary</item>
        <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
        <item name="colorAccent">@color/colorAccent</item>
    </style>

    <style name="AppTheme.SplashScreen" parent="AppTheme">
        <item name="android:windowBackground">@drawable/splash</item>
        <item name="android:windowTranslucentStatus">true</item>
        <item name="android:windowTranslucentNavigation">true</item>
    </style>

    ...

</resources>

small tip: no need to define parent="AppTheme" if you prefixing style name with parent name.
<style name="AppTheme.SplashScreen"> is enough

@sewerk, yep, thanks