ripple_effect.xml

<!-- ripple effect API 21 -->

<?xml version="1.0" encoding="utf-8"?>
<ripple
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:color="@color/colorRipple">     <!-- ripple color -->

    <!-- for Button -->
    <item>
        <shape android:shape="rectangle">
            <corners android:radius="3dp" />
            <solid android:color="@color/colorPrimary"/>
        </shape>
    </item>

</ripple>

<!-- ripple effect < API 21 -->

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">

    <item android:state_pressed="true">
        <shape android:shape="rectangle">
            <corners android:radius="3dp" />
            <solid android:color="@color/colorRipple" />
        </shape>
    </item>
    <item android:state_focused="true">
        <shape android:shape="rectangle">
            <corners android:radius="3dp" />
            <solid android:color="@color/colorPrimary" />
        </shape>
    </item>
    <item>
        <shape android:shape="rectangle">
            <corners android:radius="3dp" />
            <solid android:color="@color/colorPrimary" />
        </shape>
    </item>

</selector>