title: ios - How to change app color theme
body: <p>Hi I'm new to ios dev and I'm trying to make buttons, which are in my 'settings viewController', change the color theme of the entire app (i.e. background color).
  The code below is currently in the appDelegate class, as I found that it works great for this purpose.</p>
  
  <p>So now I'm not sure how to have the buttons in my 'settings viewController' activate the code in the appDelegate. Should I be setting a listener for the event? use closures? </p>
  
  <p>Any help is appreciated. please post code solutions if possible it really helps!:)</p>
  
  <pre><code>func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -&gt; Bool {
  
      UINavigationBar.appearance().tintColor = UIColor.whiteColor()
      UINavigationBar.appearance().titleTextAttributes = [NSForegroundColorAttributeName:UIColor.whiteColor()]
      Style.greenTheme()
  }
  </code></pre>