title: How to change the color of a button?
body: <p>I'm new to android programming. How do I change the color of a button?</p>
  
  <pre><code>&lt;Button
      android:id="@+id/btn"
      android:layout_width="55dp"
      android:layout_height="50dp"
      android:layout_gravity="center"
      android:text="Button Text"
      android:paddingBottom="20dp"/&gt;
  </code></pre>