title: Button Background Selector
body: <p>I try to switch the background of Buttons if they are pressed. I build a Selector like the answer suggested here: <a href="https://stackoverflow.com/questions/1521640/standard-android-button-with-a-different-color">Standard Android Button with a different color</a> </p>
  
  <p>Finally I want to put <code>GradientDrawables</code> inside, but for debugging purposes I just set a color, to check if it works. 
  Here is my Selector</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;selector
    xmlns:android="http://schemas.android.com/apk/res/android"&gt;
  
    &lt;item android:drawable="@color/red"/&gt;
    &lt;item 
      android:state_focused="true"
      android:drawable="@color/white"/&gt;
     &lt;item 
      android:state_pressed="true"
      android:drawable="@color/white"/&gt;
  &lt;/selector&gt;
  </code></pre>
  
  <p>Unfortunatly this doesn't work. I set the Selector as Button background and only see them in red color. What Am I doing wrong (Build Target 2.1)</p>