drawable_selector.xml

<!--On-->
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
    <item>
        <shape
            android:innerRadius="0dp"
            android:shape="ring"
            android:thickness="4dp"
            android:useLevel="false">
            <solid android:color="@color/colorPrimary" />
        </shape>

    </item>
</layer-list>


<!--Off-->
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
    <item>
        <shape
            android:innerRadius="0dp"
            android:shape="ring"
            android:thickness="4dp"
            android:useLevel="false">
            <solid android:color="@color/colorGray" />
        </shape>

    </item>
</layer-list>

<!--Selector-->
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:drawable="@drawable/dots_on" android:state_selected="true" />
    <item android:drawable="@drawable/dots_off" android:state_selected="false" />
</selector>