custom_color_cult.xml

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@color/blue"> <!-- Change your color here -->

    <com.github.ppamorim.cult.CultView
        android:id="@+id/cult_view"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:toolbar_height="64dp"
        app:inner_padding="4dp"
        app:content_view="@layout/layout_base"/>

</FrameLayout>