title: Buttons on navigation bar do not pick up window tint colour
body: <h2>Note, I've recently come back to this and it seems to have been fixed in more recent versions of the SDK, without me having to implement anything except the code in the question.  Many thanks to all who answered.</h2>
  
  <p>I have an Objective-C app that runs on the iPad and displays a view controller with a modal presentation style of <code>UIModalPresentationPageSheet</code>:</p>
  
  <pre><code>UINavigationController *editorNavigationController = [[UINavigationController alloc] initWithRootViewController:editorViewController];
  editorNavigationController.modalPresentationStyle = UIModalPresentationPageSheet;
  [navigationController presentViewController:editorNavigationController animated:YES completion:nil];
  </code></pre>
  
  <p>When this view controller is displayed the buttons in the navigation bar are purple, which I assume has been picked up from the window's tint colour, which is what I want.</p>
  
  <p>Later I need to display another view controller over the top, that fills the whole window:</p>
  
  <pre><code>UINavigationController *previewNavigationController = [[UINavigationController alloc]initWithRootViewController:myPreviewViewController];
  [owningViewController presentViewController:previewNavigationController animated:YES completion:nil];
  </code></pre>
  
  <p>The problem I have is that when <code>myPreviewController</code> is displayed, the buttons in the navigation bar are grey.  I've tried reinstating the colour on the new navigation controller:</p>
  
  <pre><code>previewNavigationController.navigationBar.tintColor = [UIColor colorWithRed:123/255.0 green:26/255.0 blue:69/255.0 alpha:1];
  </code></pre>
  
  <p>but without any joy.</p>
  
  <p>How can I get the buttons to have the correct colour?  Can I get the new navigation controller to pick up the window tint colour automatically, or do I have to set it explicitly?  Is this something to do with presenting the second navigation controller over the top of one that uses <code>UIModalPresentationPageSheet</code>?</p>
  
  <p>Any help much appreciated!  Thanks,</p>
  
  <p>Paul</p>