NEW: Master Swift design patterns with my latest book! >>

How to convert a HTML name string into a UIColor

Written by Paul Hudson    @twostraws

HTML color names let you use familiar titles like "steel blue" and "mint cream" rather than hex values, but sadly these standardized names aren't available in iOS – or at least not by default. Fortunately, it's easy to add an extension to UIColor that maps these names to hexadecimal color values, then add another extension to convert hex colors to UIColors. Here's the code:

extension UIColor {
    public convenience init?(hexString: String) {
        let r, g, b, a: CGFloat

        if hexString.hasPrefix("#") {
            let start = hexString.index(hexString.startIndex, offsetBy: 1)
            let hexColor = hexString.substring(from: start)

            if hexColor.count == 8 {
                let scanner = Scanner(string: hexColor)
                var hexNumber: UInt64 = 0

                if scanner.scanHexInt64(&hexNumber) {
                    r = CGFloat((hexNumber & 0xff000000) >> 24) / 255
                    g = CGFloat((hexNumber & 0x00ff0000) >> 16) / 255
                    b = CGFloat((hexNumber & 0x0000ff00) >> 8) / 255
                    a = CGFloat(hexNumber & 0x000000ff) / 255

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

        return nil
    }

    public convenience init?(name: String) {
        let allColors = [
            "aliceblue": "#F0F8FFFF",
            "antiquewhite": "#FAEBD7FF",
            "aqua": "#00FFFFFF",
            "aquamarine": "#7FFFD4FF",
            "azure": "#F0FFFFFF",
            "beige": "#F5F5DCFF",
            "bisque": "#FFE4C4FF",
            "black": "#000000FF",
            "blanchedalmond": "#FFEBCDFF",
            "blue": "#0000FFFF",
            "blueviolet": "#8A2BE2FF",
            "brown": "#A52A2AFF",
            "burlywood": "#DEB887FF",
            "cadetblue": "#5F9EA0FF",
            "chartreuse": "#7FFF00FF",
            "chocolate": "#D2691EFF",
            "coral": "#FF7F50FF",
            "cornflowerblue": "#6495EDFF",
            "cornsilk": "#FFF8DCFF",
            "crimson": "#DC143CFF",
            "cyan": "#00FFFFFF",
            "darkblue": "#00008BFF",
            "darkcyan": "#008B8BFF",
            "darkgoldenrod": "#B8860BFF",
            "darkgray": "#A9A9A9FF",
            "darkgrey": "#A9A9A9FF",
            "darkgreen": "#006400FF",
            "darkkhaki": "#BDB76BFF",
            "darkmagenta": "#8B008BFF",
            "darkolivegreen": "#556B2FFF",
            "darkorange": "#FF8C00FF",
            "darkorchid": "#9932CCFF",
            "darkred": "#8B0000FF",
            "darksalmon": "#E9967AFF",
            "darkseagreen": "#8FBC8FFF",
            "darkslateblue": "#483D8BFF",
            "darkslategray": "#2F4F4FFF",
            "darkslategrey": "#2F4F4FFF",
            "darkturquoise": "#00CED1FF",
            "darkviolet": "#9400D3FF",
            "deeppink": "#FF1493FF",
            "deepskyblue": "#00BFFFFF",
            "dimgray": "#696969FF",
            "dimgrey": "#696969FF",
            "dodgerblue": "#1E90FFFF",
            "firebrick": "#B22222FF",
            "floralwhite": "#FFFAF0FF",
            "forestgreen": "#228B22FF",
            "fuchsia": "#FF00FFFF",
            "gainsboro": "#DCDCDCFF",
            "ghostwhite": "#F8F8FFFF",
            "gold": "#FFD700FF",
            "goldenrod": "#DAA520FF",
            "gray": "#808080FF",
            "grey": "#808080FF",
            "green": "#008000FF",
            "greenyellow": "#ADFF2FFF",
            "honeydew": "#F0FFF0FF",
            "hotpink": "#FF69B4FF",
            "indianred": "#CD5C5CFF",
            "indigo": "#4B0082FF",
            "ivory": "#FFFFF0FF",
            "khaki": "#F0E68CFF",
            "lavender": "#E6E6FAFF",
            "lavenderblush": "#FFF0F5FF",
            "lawngreen": "#7CFC00FF",
            "lemonchiffon": "#FFFACDFF",
            "lightblue": "#ADD8E6FF",
            "lightcoral": "#F08080FF",
            "lightcyan": "#E0FFFFFF",
            "lightgoldenrodyellow": "#FAFAD2FF",
            "lightgray": "#D3D3D3FF",
            "lightgrey": "#D3D3D3FF",
            "lightgreen": "#90EE90FF",
            "lightpink": "#FFB6C1FF",
            "lightsalmon": "#FFA07AFF",
            "lightseagreen": "#20B2AAFF",
            "lightskyblue": "#87CEFAFF",
            "lightslategray": "#778899FF",
            "lightslategrey": "#778899FF",
            "lightsteelblue": "#B0C4DEFF",
            "lightyellow": "#FFFFE0FF",
            "lime": "#00FF00FF",
            "limegreen": "#32CD32FF",
            "linen": "#FAF0E6FF",
            "magenta": "#FF00FFFF",
            "maroon": "#800000FF",
            "mediumaquamarine": "#66CDAAFF",
            "mediumblue": "#0000CDFF",
            "mediumorchid": "#BA55D3FF",
            "mediumpurple": "#9370D8FF",
            "mediumseagreen": "#3CB371FF",
            "mediumslateblue": "#7B68EEFF",
            "mediumspringgreen": "#00FA9AFF",
            "mediumturquoise": "#48D1CCFF",
            "mediumvioletred": "#C71585FF",
            "midnightblue": "#191970FF",
            "mintcream": "#F5FFFAFF",
            "mistyrose": "#FFE4E1FF",
            "moccasin": "#FFE4B5FF",
            "navajowhite": "#FFDEADFF",
            "navy": "#000080FF",
            "oldlace": "#FDF5E6FF",
            "olive": "#808000FF",
            "olivedrab": "#6B8E23FF",
            "orange": "#FFA500FF",
            "orangered": "#FF4500FF",
            "orchid": "#DA70D6FF",
            "palegoldenrod": "#EEE8AAFF",
            "palegreen": "#98FB98FF",
            "paleturquoise": "#AFEEEEFF",
            "palevioletred": "#D87093FF",
            "papayawhip": "#FFEFD5FF",
            "peachpuff": "#FFDAB9FF",
            "peru": "#CD853FFF",
            "pink": "#FFC0CBFF",
            "plum": "#DDA0DDFF",
            "powderblue": "#B0E0E6FF",
            "purple": "#800080FF",
            "rebeccapurple": "#663399FF",
            "red": "#FF0000FF",
            "rosybrown": "#BC8F8FFF",
            "royalblue": "#4169E1FF",
            "saddlebrown": "#8B4513FF",
            "salmon": "#FA8072FF",
            "sandybrown": "#F4A460FF",
            "seagreen": "#2E8B57FF",
            "seashell": "#FFF5EEFF",
            "sienna": "#A0522DFF",
            "silver": "#C0C0C0FF",
            "skyblue": "#87CEEBFF",
            "slateblue": "#6A5ACDFF",
            "slategray": "#708090FF",
            "slategrey": "#708090FF",
            "snow": "#FFFAFAFF",
            "springgreen": "#00FF7FFF",
            "steelblue": "#4682B4FF",
            "tan": "#D2B48CFF",
            "teal": "#008080FF",
            "thistle": "#D8BFD8FF",
            "tomato": "#FF6347FF",
            "turquoise": "#40E0D0FF",
            "violet": "#EE82EEFF",
            "wheat": "#F5DEB3FF",
            "white": "#FFFFFFFF",
            "whitesmoke": "#F5F5F5FF",
            "yellow": "#FFFF00FF",
            "yellowgreen": "#9ACD32FF"
        ]

        let cleanedName = name.replacingOccurrences(of: " ", with: "").lowercased()

        if let hexString = allColors[cleanedName] {
            self.init(hexString: hexString)
        } else {
            return nil
        }
    }
}

With that done, here's how you create a color:

let steelBlue = UIColor(name: "steel blue")

Available from iOS 2.0

Did this solution work for you? Please pass it on!

Other people are reading…

About the Swift Knowledge Base

This is part of the Swift Knowledge Base, a free, searchable collection of solutions for common iOS questions.

Get my latest video for free

Learn about value types, functional programming, and protocol-oriented programming in this new video – it's free!

Click here to visit the Hacking with Swift store >>