Only half of jQuery animation is running
<p>Only the changes in width in this jQuery animation is running, why isn't the color change animation also happening?</p>

<pre><code>$('#code').animate({ 
  'background':'#dddddd', 
  'background':'rgb(221, 221, 221)', 
  'width':'16px', 
  'width':'1rem' 
});
</code></pre>
