title: Why is "rgb (224, 226, 213)" an invalid property value?
body: <p>Why can't any browser apply this color rgb rule?</p>
  
  <p><strong>HTML</strong></p>
  
  <pre><code>&lt;header&gt;
      &lt;h1&gt;Header&lt;/h1&gt;
  &lt;/header&gt;
  </code></pre>
  
  <p><strong>CSS</strong></p>
  
  <pre><code>header h1 {
      background-color: red;
      color: rgb (224, 226, 213);
  }
  </code></pre>
  
  <p>Chrome Web Developer tools is telling me that it's an invalid property value, but I can't understand why. You can see the result in <a href="http://jsfiddle.net/ZwXdA/">JSFiddle</a>. </p>