title: UINavigationBar change title text color and font size
body: <p>I want to change navigation title's font and color..so, for that i've done this below code..but its not working...</p>
  
  <pre><code>if (SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(@"7")) {
  
  
      NSDictionary *navbarTitleTextAttributes = [NSDictionary dictionaryWithObjectsAndKeys:
                                                 [UIColor whiteColor],
                                                 NSForegroundColorAttributeName,
                                                 [UIFont fontWithName:@"MyFavoriteFont" size:20.0],
                                                 NSFontAttributeName,
                                                 nil];
      [[UINavigationBar appearance] setTitleTextAttributes:navbarTitleTextAttributes];
      NSLog(@"setTitleTextAttributes");
  }
  </code></pre>
  
  <p>why this code is not working?</p>