Material effect on button with background color

I am using Android v21 support library.

I have created a button with custom background color. The Material design effects like ripple, reveal are gone (except the elevation on click) when I use the back ground color.

 <Button
 style="?android:attr/buttonStyleSmall"
 android:background="?attr/colorPrimary"
 android:textColor="@color/white"
 android:textAllCaps="true"
 android:layout_width="fill_parent"
 android:layout_height="wrap_content"
 android:text="Button1"
 />

The following is a normal button and the effects are working just fine.

<Button
 style="?android:attr/buttonStyleSmall"
 android:layout_width="fill_parent"
 android:layout_height="wrap_content"
 android:textAllCaps="true"
 android:text="Button1"
/>