Get Slightly Lighter and Darker Color from UIColor

Question

I was looking to be able to turn any UIColor into a gradient. The way I am intending to do this is by using Core Graphics to draw a gradient. What I am trying to do is to ge

Answer 1

Swift 5

extension UIColor {

func lighter(by percentage:CGFloat=30.0) -> UIColor? {
    return self.adjust(by: abs(percentage) )
}

func darker(by percentage:CGFloat=30.0) -> UIColor? {
    return self.adjust(by: -1 * abs(percentage) )
}

func adjust(by percentage:CGFloat=30.0) -> UIColor? {
    var r:CGFloat=0, g:CGFloat=0, b:CGFloat=0, a:CGFloat=0;
    if self.getRed(&r, green: &g, blue: &b, alpha: &a) {
        return UIColor(red: min(r + percentage/100, 1.0),
                       green: min(g + percentage/100, 1.0),
                       blue: min(b + percentage/100, 1.0),
                       alpha: a)
    } else {
        return nil
     }
   }
}