title: change color navigation controller in a popover
body: <p>I'm having a problem with trying to change the colour of my navigation controller inside my popoverController.<br>
  I'm trying to do something like this:</p>
  
  <pre><code>if (self.popoverController == nil) {
      ArtistsViewController *artistsViewController = 
      [[ArtistsViewController alloc]      
       initWithNibName:@"ArtistsViewController" 
       bundle:[NSBundle mainBundle]]; 
  
      artistsViewController.navigationItem.title = @"Artists";
      UINavigationController *navController = 
      [[UINavigationController alloc] 
       initWithRootViewController:artistsViewController];
  
  
      UIPopoverController *popover = 
      [[UIPopoverController alloc] 
       initWithContentViewController:artistsViewController.navigationController];
      artistsViewController.navigationController.navigationBar.tintColor=[UIColor greenColor];
  
      popover.delegate = self;
      [artistsViewController release];
      [navController release];
  
      self.popoverController = popover;
      [popover release];
  }
  
  [self.popoverController 
   presentPopoverFromBarButtonItem:sender                                    
   permittedArrowDirections:UIPopoverArrowDirectionAny 
   animated:YES];
  </code></pre>
  
  <p>but it doesn't work. any suggestions?</p>