title: Force view controller to reload to refresh UIAppearance changes
body: <p>I have been searching for quite a while and can't find an answer. I am working on an iOS app and have a modal settings page that appears on the tap of a button and returns with a segue.
  One of the options I would like to implement is a color scheme setting. I really want to avoid manually changing the color for every element on the page.</p>
  
  <p>Apple has a <a href="https://developer.apple.com/library/iOS/documentation/UIKit/Reference/UIAppearance_Protocol/Reference/Reference.html" rel="noreferrer">UIAppearance</a> protocol for this sort of thing (so I can set the text color of all buttons, etc.
  Their documentation says:</p>
  
  <blockquote>
    <p>Note: iOS applies appearance changes when a view enters a window, it doesn’t change the appearance of a view that’s already in a window. To change the appearance of a view that’s currently in a window, remove the view from the view hierarchy and then put it back.</p>
  </blockquote>
  
  <p>My question is how to do this. I have tried calling viewWillAppear and setNeedsDisplay without luck.</p>