main_layout.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="match_parent"
    android:layout_height="match_parent">
<ImageView
    android:id="@+id/image"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:src="@drawable/tiger"
    android:layout_weight="4"/>

    <LinearLayout 
        android:orientation="vertical" android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_weight="6">
    
    <Button
        android:id="@+id/btnVibrant"
        android:text="Vibrant"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_weight="1"/>

    <Button
        android:id="@+id/btnVibrantDark"
        android:text="Vibrant Dark"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_weight="1"/>

    <Button
        android:id="@+id/btnVibrantMuted"
        android:text="Vibrant Muted"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_weight="1"/>

    <Button
        android:id="@+id/btnMuted"
        android:text="Muted"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_weight="1"/>

    <Button
        android:id="@+id/btnMutedDark"
        android:text="Muted Dark"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_weight="1"/>

    <Button
        android:id="@+id/btnMutedLight"
        android:text="Muted Light"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_weight="1"/>

</LinearLayout>
</LinearLayout>