title: Angular2 how to change color of a disabled button
body: <p>i have this button</p>
  
  <pre><code>&lt;button class="btn" [disabled]="true"&gt;
      &lt;i class="fa fa-heart" aria-hidden="true"&gt;&lt;/i&gt; Like
  &lt;/button&gt;
  </code></pre>
  
  <p>I want it to be green when disabled but don't know how to do it </p>