ios: change the colors of a UIImage

The easiest and shortest:

Way to do that in case when you dealing with UIImageView:

Obj-C:

theImageView.image = [theImageView.image imageWithRenderingMode:UIImageRenderingModeAlwaysTemplate];
[theImageView setTintColor:[UIColor redColor]];

Swift:

let theImageView = UIImageView(image: UIImage(named:"foo")!.imageWithRenderingMode(UIImageRenderingMode.AlwaysTemplate))
theImageView.tintColor = UIColor.redColor()