extension UIColor { convenience init(hexaString: String, alpha: CGFloat = 1) { let chars = Array(hexaString.dropFirst()) self.init(red: .init(strtoul(String(chars[0...1]),nil,16))/255, green: .init(strtoul(String(chars[2...3]),nil,16))/255, blue: .init(strtoul(String(chars[4...5]),nil,16))/255, alpha: alpha)}
}
let redColor = UIColor(hexaString: "#FF0000") // r 1,0 g 0,0 b 0,0 a 1,0
let transparentRed = UIColor(hexaString: "#FF0000", alpha: 0.5) // r 1,0 g 0,0 b 0,0 a 0,5