How can I modify a UIColor's hue, brightness and saturation?

You can call getHue:saturation:brightness:alpha: on your color, then adjust the values, then create a new color with your adjusted components using +[UIColor colorWithHue:saturation:brightness:alpha:]

CGFloat hue, saturation, brightness, alpha ;BOOL ok = [ <color> getHue:&hue saturation:&saturation brightness:&brightness alpha:&alpha ] ;if ( !ok ) {     // handle error }// ... adjust components..UIColor * newColor = [ UIColor colorWithHue:hue saturation:saturation brightness:brightness alpha:alpha ] ;

Here is swift UIColor extension you might find useful:

extension UIColor {    func modified(withAdditionalHue hue: CGFloat, additionalSaturation: CGFloat, additionalBrightness: CGFloat) -> UIColor {        var currentHue: CGFloat = 0.0        var currentSaturation: CGFloat = 0.0        var currentBrigthness: CGFloat = 0.0        var currentAlpha: CGFloat = 0.0        if self.getHue(&currentHue, saturation: &currentSaturation, brightness: &currentBrigthness, alpha: &currentAlpha){            return UIColor(hue: currentHue + hue,                           saturation: currentSaturation + additionalSaturation,                           brightness: currentBrigthness + additionalBrightness,                           alpha: currentAlpha)        } else {            return self        }    }}

Unfortunately it's quite a hassle to change any of the hsba or rgba values of a UIColor by default. Using HandyUIKit (install it via Carthage) makes your life a lot easier:

import HandyUIKit  // each line creates a new UIColor object with the new valuecolor.change(.hue,        to: 0.1)color.change(.brightness, to: 0.2)color.change(.saturation, to: 0.3)color.change(.alpha,      to: 0.4)// chaining them returns a single new object with all values changedcolor.change(.hue,        to: 0.5)     .change(.brightness, to: 0.6)     .change(.saturation, to: 0.7)

There are also options to apply relative changes:

// create a new UIColor object with hue & brightness increased by 0.2color.change(.hue,        by: 0.2)     .change(.brightness, by: 0.2)

The library also adds some other handy UI features into your project – checkout its README on GitHub for more details.

I hope it helps!