Create a gradient UIColor from an array of colors.

Create color with gradient

func colorWithGradient(frame: CGRect, colors: [UIColor]) -> UIColor {
    
    // create the background layer that will hold the gradient
    let backgroundGradientLayer = CAGradientLayer()
    backgroundGradientLayer.frame = frame
     
    // we create an array of CG colors from out UIColor array
    let cgColors = colors.map({$0.CGColor})
    
    backgroundGradientLayer.colors = cgColors
    
    UIGraphicsBeginImageContext(backgroundGradientLayer.bounds.size)
    backgroundGradientLayer.renderInContext(UIGraphicsGetCurrentContext())
    let backgroundColorImage = UIGraphicsGetImageFromCurrentImageContext()
    UIGraphicsEndImageContext()
    
    return UIColor(patternImage: backgroundColorImage)
}