title: How to set backgroundColor for navigationItem?
body: <p>I'm trying to format the navigationItem at the top of my main tableView. I've managed to set the title that is displayed by this code</p>
  
  <pre><code>[[self navigationItem] setTitle:@"MyTitle"];
  </code></pre>
  
  <p>But I haven't found a way to access the backgroundColor. I'd like to something like this</p>
  
  <pre><code>[[self navigationItem] setBackgroundColor:[UIColor colorRed]];
  </code></pre>
  
  <p>But this doesn't work. Any other ideas?</p>