It is a code that I wrote in my drawable folder, but it won't work either.
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:state_pressed="true">
        <shape>
            <solid android:color="#EF9191" />
            <corners android:radius="8dp" />
        </shape>
    </item>
    <item android:state_pressed="false">
        <shape>
            <solid android:color="#ED3939" />
            <corners android:radius="8dp" />
        </shape>
    </item>
</selector>