title: Unable to set navigation bar color of modal view controller
body: <p>I'm presenting a modal view controller like this on iPhone / iOS 8:</p>
  
  <pre><code>UIApplication*          application        = [UIApplication sharedApplication];
  UIWindow*               window             = application.windows[0];
  UIViewController*       rootViewController = window.rootViewController;
  SomeViewController*     someViewController;
  UINavigationController* navigationController;
  
  someViewController   = [[SomeViewController alloc] init];
  navigationController = [[UINavigationController alloc] initWithRootViewController:someViewController];
  
  // Set everything to black.
  navigationController.navigationBar.barTintColor = [UIColor blackColor];
  navigationController.navigationBar.tintColor    = [UIColor blackColor];
  navigationController.navigationBar.barStyle     = UIBarStyleBlack;
  
  navigationController.modalTransitionStyle = UIModalTransitionStyleCoverVertical;
  [rootViewController presentViewController:navigationController animated:YES completion:nil];
  </code></pre>
  
  <p><code>SomeViewController</code> is an empty/fresh view controller that does nothing (except for also trying to set the navigation bar to black, without success).</p>
  
  <p>This is in an app using a storyboard, and which has <a href="https://github.com/nverinaud/NVSlideMenuController" rel="nofollow">NVSlideMenuController</a> as the window's root.</p>
  
  <p>What happens is that the view controller is presented, but the navigation bar is/seems fully transparent, because when I set <code>someViewController</code>'s background color to red, the whole screen is red (except the title).  The rest of the app has a transparent navigation bar.</p>
  
  <p>Another thing that might be related is that when app is going to background (with iPhone home button) and then foreground again, the view controller is no longer visible.</p>
  
  <p>What am I missing or doing wrong here?</p>