Swift 4: UIColor(hex: String) extension

gistfile1.txt

// Inspired by https://stackoverflow.com/questions/24263007/how-to-use-hex-colour-values, merging Swift 4 + extension examples
extension UIColor {
  
  convenience init (hex:String) {
    var cString:String = hex.trimmingCharacters(in: .whitespacesAndNewlines).uppercased()
    
    if (cString.hasPrefix("#")) {
      cString.remove(at: cString.startIndex)
    }
    
    if ((cString.count) != 6) {
      self.init(cgColor: UIColor.gray.cgColor)
    } else { 
      var rgbValue:UInt32 = 0
      Scanner(string: cString).scanHexInt32(&rgbValue)
      
      self.init(
        red: CGFloat((rgbValue & 0xFF0000) >> 16) / 255.0,
        green: CGFloat((rgbValue & 0x00FF00) >> 8) / 255.0,
        blue: CGFloat(rgbValue & 0x0000FF) / 255.0,
        alpha: CGFloat(1.0)
      )
    }
  }
}