How to make a button flash or blink?

Question

I am trying to change a button\'s color (just a flash/blink) to green when a scan is correct and red when there\'s a problem. I am able to do this with a view like so

Answer 1

Swift 3.0

func animateFlash() {        
    flashView.alpha = 0
    flashView.isHidden = false
    UIView.animate(withDuration: 0.3, animations: { flashView.alpha = 1.0 }) { finished in flashView.isHidden = true }
}