Depois de adicionar cor a um botão do Android, ele perde o efeito cascata que faz com que o usuário sinta que há um clique responsivo. Como faço para corrigir isso? Pesquisei muitas soluções, mas não consegui encontrar uma definitiva que não fosse ambígua.

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
                xmlns:tools="http://schemas.android.com/tools"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                tools:context=".ClockInOutFragment">


    <AnalogClock
        android:id="@+id/clock"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentEnd="true"
        android:layout_alignParentRight="true"
        android:layout_alignParentTop="true"
        android:layout_toRightOf="@+id/date_and_time"/>


    <RelativeLayout
        android:id="@+id/date_and_time"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_margin="10dp">

        <TextView
            android:id="@+id/time_digits"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="12:10"
            android:textSize="45sp"/>

        <TextView
            android:id="@+id/am_pm"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignBaseline="@+id/time_digits"
            android:layout_toRightOf="@+id/time_digits"
            android:paddingLeft="3dp"
            android:text="PM"
            android:textSize="20sp"/>

        <TextView
            android:id="@+id/date"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_below="@+id/time_digits"
            android:text="Mon, July 11"
            android:textSize="22sp"/>
    </RelativeLayout>

    <!--Clock in and out buttons-->
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_centerHorizontal="true"
        android:orientation="horizontal">

        <Button
            android:id="@+id/textView3"
            android:layout_width="0dp"
            android:layout_height="56dp"
            android:layout_weight="1"
            android:background="#4CAF50"
            android:gravity="center"
            android:text="Clock In"
            android:textAppearance="?android:attr/textAppearanceLarge"
            android:textColor="#FFFFFF"/>

        <!--Divider between the clock in and out button-->
        <View
            android:layout_width="1dp"
            android:layout_height="match_parent"
            android:background="#B6B6B6"/>

        <Button
            android:id="@+id/textView4"
            android:layout_width="0dp"
            android:layout_height="56dp"
            android:layout_weight="1"
            android:background="#FF5252"
            android:gravity="center"
            android:text="Clock Out"
            android:textAppearance="?android:attr/textAppearanceLarge"
            android:textColor="#FFFFFF"/>
    </LinearLayout>


</RelativeLayout>