tachiyomi/app/src/main/res/values-v27/themes.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <style name="Base.V27.Theme.Tachiyomi.Light" parent="Base.Theme.Tachiyomi.Light">
        <item name="android:navigationBarColor">?attr/colorPrimary</item>
        <item name="android:windowLightNavigationBar">true</item>
    </style>

    <style name="Theme.Tachiyomi.Light" parent="Base.V27.Theme.Tachiyomi.Light" />
</resources>