title: UIColor colorWithPatternImage uses only one image
body: <p>I'm trying to give <code>tableviewcell</code>'s different <code>backgroundColor</code>s with <code>colorwithPatternImage</code> and it is not working as expected. The documentation says nothing about only being able to use one pattern at a time.</p>
  
  <p>Say I have 3 rows and I set the background like so:</p>
  
  <pre><code>Cell1.backgroundColor = [UIColor colorWithPatternImage: [UIImage imageNamed: @"red.png"]];
  
  Cell2.backgroundColor = [UIColor colorWithPatternImage: [UIImage imageNamed: @"green.png"]];
  
  Cell3.backgroundColor = [UIColor colorWithPatternImage: [UIImage imageNamed: @"blue.png"]];
  </code></pre>
  
  <p>All 3 rows would be red. It's as if there is some global color that is being returned.</p>
  
  <p><code>colorWithPatternImage</code> returns <code>kCGColorSpaceModelPattern 1</code> for each call no matter what image is passed in. If it was true that you only have 1 global pattern at a time, then the color should be the last one set, in other words blue.</p>
  
  <p>This makes no sense. Does anyone have any inside expertise on what Apple is doing here?</p>
  
  <p><strong>EDIT</strong>
  I even use a different pattern in a completely separate view and it still affects the other view's patterns. I am convinced, though the documentation doesn't state this, that you are limited to one UIColor image pattern at a time. Sad.</p>