Add a colourful image as the right bar button item in a navigation bar

Question

I add a right navigation bar item that has a coloured background image:

let rightButton = UIBarButtonItem(image: UIImage(named: "avatar")!,
                                  style: UIBarButtonItemStyle.Plain, 
                                  target: self,     
                                  action: #selector(self.rightNavBarItemAction))

navigationItem.rightBarButtonItem = rightButton

Instead of having the image as the background of the button (in colours), I get a white placeholder.

Answer 1

You can update the image's rendering mode to UIImageRenderingMode.alwaysOriginal.

Swift 4.2:

let img = UIImage(named: "avatar")!.withRenderingMode(.alwaysOriginal)
let rightButton = UIBarButtonItem(image: img,
                                      style: UIBarButtonItem.Style.Plain,
                                      target: self,
                                      action: #selector(self.rightNavBarItemAction))

Swift 4:

let img = UIImage(named: "avatar")!.withRenderingMode(.alwaysOriginal)
let rightButton = UIBarButtonItem(image: img,
                                      style: UIBarButtonItemStyle.Plain,
                                      target: self,
                                      action: #selector(self.rightNavBarItemAction))

Swift 3:

let img = UIImage(named: "avatar")!.imageWithRenderingMode(UIImageRenderingMode.AlwaysOriginal);
let rightButton = UIBarButtonItem(image: img,
                                      style: UIBarButtonItemStyle.Plain,
                                      target: self,
                                      action: #selector(self.rightNavBarItemAction))

Alternatively you can set a custom view as in Vladimir's answer.