Get lighter and darker color variations for a given UIColor

Question

How to get different lighter and darker variations of a given UIColor in Swift?

Answer 1

To save anyone typing, the simple practical version is just

extension UIColor {

    var darker: UIColor {

    var h: CGFloat = 0, s: CGFloat = 0, b: CGFloat = 0, a: CGFloat = 0

        guard self.getHue(&h, saturation: &s, brightness: &b, alpha: &a) else {
            print("** some problem demuxing the color")
            return .gray
        }

        let nudged = b * 0.5

        return UIColor(hue: h, saturation: s, brightness: nudged, alpha: a)
    }
}

use like

something.color = .yellow.darker

or

backgroundColor = backgroundColor.darker

On a large project .................

You should definitely extend Apple's pattern:

.withAlphaComponent(_ alpha: CGFloat)

So, have:

.withBrightnessComponent(_ alpha: CGFloat)

and distinctly

.withBrightnessComponentAdjustedBy(percentage: CGFloat)

and/or

.withBrightnessComponentMultipliedBy(factor: CGFloat)