An extension of the iOS class UIColor to provide conversion to and from HSB (hue, saturation, brightness) colors.

UIColor+HSB.swift

/// An extension to provide conversion to and from HSB (hue, saturation, brightness) colors.
extension UIColor {

    /// The HSB (hue, saturation, brightness) components of a color.
    struct HSB: Hashable {

        /// The hue component of the color, in the range [0, 360°].
        var hue: CGFloat
        /// The saturation component of the color, in the range [0, 100%].
        var saturation: CGFloat
        /// The brightness component of the color, in the range [0, 100%].
        var brightness: CGFloat

    }

    /// The HSB (hue, saturation, brightness) components of the color.
    var hsb: HSB {
        var (h, s, b) = (CGFloat(), CGFloat(), CGFloat())
        getHue(&h, saturation: &s, brightness: &b, alpha: nil)
        
        return HSB(hue: h * 360.0,
                   saturation: s * 100.0,
                   brightness: b * 100.0)
    }

    /// Initializes a color from HSB (hue, saturation, brightness) components.
    /// - parameter hsb: The components used to initialize the color.
    /// - parameter alpha: The alpha value of the color.
    convenience init(_ hsb: HSB, alpha: CGFloat = 1.0) {
        self.init(hue: hsb.hue / 360.0,
                  saturation: hsb.saturation / 100.0,
                  brightness: hsb.brightness / 100.0,
                  alpha: alpha)
    }

}