title: fontawesome: can not change color of stacked icon
body: <p>Here is the plunker - <a href="http://plunker.co/edit/npLOW06U0aAVZmGAHv7U?p=preview" rel="nofollow">http://plunker.co/edit/npLOW06U0aAVZmGAHv7U?p=preview</a></p>
  
  <p>In <code>style.css</code>, I do</p>
  
  <pre><code>.icon-stack .icon-sign-blank: {
   color: red; 
  }
  .icon-stack .icon-trash: {
    color: white;
  }
  </code></pre>
  
  <p>but it does not changes color, what is that I am doing incorrect here?</p>