Color.swift

extension UIColor {
    convenience init(r: Int, g: Int, b: Int, a: Int = 0xFF) {
        self.init(
            red: CGFloat(r) / 255.0,
            green: CGFloat(g) / 255.0,
            blue: CGFloat(b) / 255.0,
            alpha: CGFloat(a) / 255.0
        )
    }

    convenience init(argb: UInt32) {
        self.init(
            red: CGFloat((argb >> 16) & 0xFF),
            green: CGFloat((argb >> 8) & 0xFF),
            blue: CGFloat(argb & 0xFF),
            alpha: CGFloat((argb >> 24) & 0xFF)
        )
    }

    convenience init?(fromHex: String) {
        let hexString = fromHex.trimmingCharacters(in: .whitespacesAndNewlines).replacingOccurrences(
            of: "#",
            with: ""
        )

        var argb: UInt32 = 0

        var r: CGFloat = 0.0
        var g: CGFloat = 0.0
        var b: CGFloat = 0.0
        var a: CGFloat = 1.0

        guard Scanner(string: hexString).scanHexInt32(&argb) else { return nil }

        if hexString.count == 6 {
            r = CGFloat((argb & 0xFF0000) >> 16) / 255.0
            g = CGFloat((argb & 0x00FF00) >> 8) / 255.0
            b = CGFloat(argb & 0x0000FF) / 255.0

        } else if hexString.count == 8 {
            r = CGFloat((argb & 0xFF00_0000) >> 24) / 255.0
            g = CGFloat((argb & 0x00FF0000) >> 16) / 255.0
            b = CGFloat((argb & 0x0000FF00) >> 8) / 255.0
            a = CGFloat(argb & 0x000000FF) / 255.0

        } else {
            return nil
        }

        self.init(red: r, green: g, blue: b, alpha: a)
    }
}