title: Get RGB value from UIColor presets
body: <p>I my application I pass RGB color value to server. My app uses UIColor predefined values, like [UIColor grayColor], [UIColor redColor]. I know that I can use following code:</p>
  
  <pre><code>const CGFloat *c = CGColorGetComponents(color.CGColor)
  </code></pre>
  
  <p>but only for colors that are in RBG color space, however, [UIColor grayColor] is not.</p>
  
  <p>Is there any way to get RGB values for non-RBG colors?</p>
  
  <p>Thanks!</p>