title: Change color of Back button in navigation bar
body: <p>I am trying to change the color of the Settings button to white, but can't get it to change.</p>
  
  <p>I've tried both of these:</p>
  
  <pre><code>navigationItem.leftBarButtonItem?.tintColor = UIColor.whiteColor()
  navigationItem.backBarButtonItem?.tintColor = UIColor.whiteColor()
  </code></pre>
  
  <p>but no change, it still looks like this:</p>
  
  <p><img src="https://i.stack.imgur.com/vqCQh.png" alt="enter image description here"></p>
  
  <p>How do I make that button white?</p>