Creating a UIColor

There are many ways you can create a UIColor:

Swift

Using one of the predefined colors:

let redColor = UIColor.redColor()
let blueColor: UIColor = .blueColor()

// In Swift 3, the "Color()" suffix is removed:
let redColor = UIColor.red
let blueColor: UIColor = .blue

If the compiler already knows that the variable is an instance of UIColor you can skip the type all together:

let view = UIView()
  view.backgroundColor = .yellowColor()

Using the grayscale value and the alpha:

let grayscaleColor = UIColor(white: 0.5, alpha: 1.0)

Using hue, saturation, brightness and alpha:

let hsbColor = UIColor(
    hue: 0.4,
    saturation: 0.3,
    brightness: 0.7,
    alpha: 1.0
)

Using the RGBA values:

let rgbColor = UIColor(
      red: 30.0 / 255, 
      green: 70.0 / 255, 
      blue: 200.0 / 255, 
      alpha: 1.0
  )

Using a pattern image:

let patternColor = UIColor(patternImage: UIImage(named: "myImage")!)

Objective-C

Using one of the predefined colors:

UIColor *redColor = [UIColor redColor];

Using the grayscale value and the alpha:

UIColor *grayscaleColor = [UIColor colorWithWhite: 0.5 alpha: 1.0];

Using hue, saturation, brightness and alpha: