[android] Material effect on button with background color

There are two approaches explained in the great tutorial be Alex Lockwood: http://www.androiddesignpatterns.com/2016/08/coloring-buttons-with-themeoverlays-background-tints.html:

Approach #1: Modifying the button’s background color w/ a ThemeOverlay

<!-- res/values/themes.xml -->
<style name="RedButtonLightTheme" parent="ThemeOverlay.AppCompat.Light">
    <item name="colorAccent">@color/googred500</item>
</style>

<Button
    style="@style/Widget.AppCompat.Button.Colored"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:theme="@style/RedButtonLightTheme"/>

Approach #2: Setting the AppCompatButton’s background tint

<!-- res/color/btn_colored_background_tint.xml -->
<selector xmlns:android="http://schemas.android.com/apk/res/android">

    <!-- Disabled state. -->
    <item android:state_enabled="false"
          android:color="?attr/colorButtonNormal"
          android:alpha="?android:attr/disabledAlpha"/>

    <!-- Enabled state. -->
    <item android:color="?attr/colorAccent"/>

</selector>

<android.support.v7.widget.AppCompatButton
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    app:backgroundTint="@color/btn_colored_background_tint"/>