extension UIColor {
    convenience init(hexString: String, alpha: CGFloat = 1.0) {
        let hexString: String = hexString.trimmingCharacters(in: CharacterSet.whitespacesAndNewlines)
        let scanner = Scanner(string: hexString)

        if hexString.hasPrefix("#") {
            scanner.scanLocation = 1
        }

        var color: UInt32 = 0
        scanner.scanHexInt32(&color)

        let mask = 0x0000_00FF
        let r = Int(color >> 16) & mask
        let g = Int(color >> 8) & mask
        let b = Int(color) & mask

        let red = CGFloat(r) / 255.0
        let green = CGFloat(g) / 255.0
        let blue = CGFloat(b) / 255.0

        self.init(red: red, green: green, blue: blue, alpha: alpha)
    }

    func toHexString() -> String {
        var r: CGFloat = 0
        var g: CGFloat = 0
        var b: CGFloat = 0
        var a: CGFloat = 0

        getRed(&r, green: &g, blue: &b, alpha: &a)

        let rgb: Int = (Int)(r * 255) << 16 | (Int)(g * 255) << 8 | (Int)(b * 255) << 0

        return String(format: "#%06x", rgb)
    }
}
