title: How to change the colour of an Icon from FontAwesome
body: <p>I have a menuitem with an icon specified, like this: </p>
  
  <pre><code>{
     xtype: 'menuitem',
     text: 'Random Text',
     iconCls: 'x-fa fa-briefcase',
  }
  </code></pre>
  
  <p>How do I gain access to this icon in the css and change the colour of it? </p>