I'm new to programming, is there a shorter way of achieving the same result using something like a case or caseif?

I have the code below written in my program, but I was wondering if someone could help me structure in a more summarized way as using 'case' or 'caseif' from other languages.

   var imagePressed: UIImageView
    imagePressed = self.redImage

    if color == 1 {

        imagePressed = self.redImage
    }
    if color == 2 {

        imagePressed = self.orangeImage
    }
    if color == 3 {

        imagePressed = self.yellowImage
    }
    if color == 4 {

        imagePressed = self.greenImage
    }

    imagePressed.alpha = 0.5