get complementary color to UIColor in Swift

complementaryColor.swift

// get a complementary color to this color:
func getComplementaryForColor(color: UIColor) -> UIColor {
    
    let ciColor = CIColor(color: color)
    
    // get the current values and make the difference from white:
    let compRed: CGFloat = 1.0 - ciColor.red
    let compGreen: CGFloat = 1.0 - ciColor.green
    let compBlue: CGFloat = 1.0 - ciColor.blue
    
    return UIColor(red: compRed, green: compGreen, blue: compBlue, alpha: 1.0)
}