Some useful UIColor extensions in swift

UIColorExtensions.swift

//Gets a random UIColor
extension UIColor {
    static func random() -> UIColor {
        return UIColor(red:   .random(),
                       green: .random(),
                       blue:  .random(),
                       alpha: 1.0)
    }
}

//Gets a random UIColor that's light enough to use with black text. 
extension UIColor {
    static func randomLightColor() -> UIColor {
        var thisColor = UIColor.random()
        while(!(thisColor.isLight() ?? true)){
            thisColor = UIColor.random()
        }
        return thisColor
    }
}

//gets a random CGFloat
extension CGFloat {
    static func random() -> CGFloat {
        return CGFloat(arc4random()) / CGFloat(UInt32.max)
    }
}

//returns true if a UIColor is "light"
extension UIColor {

    // Check if the color is light or dark, as defined by the injected lightness threshold.
    // Some people report that 0.7 is best. I suggest to find out for yourself.
    // A nil value is returned if the lightness couldn't be determined.
    func isLight(threshold: Float = 0.6) -> Bool? {
        let originalCGColor = self.cgColor

        // Now we need to convert it to the RGB colorspace. UIColor.white / UIColor.black are greyscale and not RGB.
        // If you don't do this then you will crash when accessing components index 2 below when evaluating greyscale colors.
        let RGBCGColor = originalCGColor.converted(to: CGColorSpaceCreateDeviceRGB(), intent: .defaultIntent, options: nil)
        guard let components = RGBCGColor?.components else {
            return nil
        }
        guard components.count >= 3 else {
            return nil
        }

        let brightness = Float(((components[0] * 299) + (components[1] * 587) + (components[2] * 114)) / 1000)
        return (brightness > threshold)
    }
}