how to change the (image color) of buttons? : <p>I have 4 bottons and I set a image as a background on each button. 
What I want to do is that the button should turn into gray when not selected
and turn into its original image color when selected. 
how can I do this??</p>

<pre><code>     &lt;Button
            android:id="@+id/btn_settingTab"
            android:layout_width="35dp"
            android:layout_height="35dp"
            android:background="@drawable/setting_icon"
            android:layout_centerHorizontal="true"/&gt;
</code></pre>
