你可以创建UIColor的扩展类:-

扩展UIColor {

// MARK: - getColorFromHex ／** 此函数将颜色十六进制代码转换为RGB。

- parameter color  hex string.

- returns: RGB color code.
*/
class func getColorFromHex(hexString:String)->UIColor{

    var rgbValue : UInt32 = 0
    let scanner:NSScanner =  NSScanner(string: hexString)

    scanner.scanLocation = 1
    scanner.scanHexInt(&rgbValue)

    return UIColor(red: CGFloat((rgbValue & 0xFF0000) >> 16) / 255.0, green: CGFloat((rgbValue & 0x00FF00) >> 8) / 255.0, blue: CGFloat(rgbValue & 0x0000FF) / 255.0, alpha: CGFloat(1.0))
}

}

试试这个:这段代码将从十六进制颜色字符串返回UIColor

- (UIColor*)colorWithHexString:(NSString*)hex  
{  
    NSString *cString = [[hex stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]] uppercaseString];  

    // String should be 6 or 8 characters  
    if ([cString length] < 6) return [UIColor grayColor];  

    // strip 0X if it appears  
    if ([cString hasPrefix:@"0X"]) cString = [cString substringFromIndex:2];  

    if ([cString length] != 6) return  [UIColor grayColor];  

    // Separate into r, g, b substrings  
    NSRange range;  
    range.location = 0;  
    range.length = 2;  
    NSString *rString = [cString substringWithRange:range];  

    range.location = 2;  
    NSString *gString = [cString substringWithRange:range];  

    range.location = 4;  
    NSString *bString = [cString substringWithRange:range];  

    // Scan values  
    unsigned int r, g, b;  
    [[NSScanner scannerWithString:rString] scanHexInt:&r];  
    [[NSScanner scannerWithString:gString] scanHexInt:&g];  
    [[NSScanner scannerWithString:bString] scanHexInt:&b];  

    return [UIColor colorWithRed:((float) r / 255.0f)  
                           green:((float) g / 255.0f)  
                            blue:((float) b / 255.0f)  
                           alpha:1.0f];  
}

下面是Swift 1.2版本，作为UIColor的扩展。这允许你这样做

let redColor = UIColor(hex: "#FF0000")

我觉得这是最自然的做法。

extension UIColor {
  // Initialiser for strings of format '#_RED_GREEN_BLUE_'
  convenience init(hex: String) {
    let redRange    = Range<String.Index>(start: hex.startIndex.advancedBy(1), end: hex.startIndex.advancedBy(3))
    let greenRange  = Range<String.Index>(start: hex.startIndex.advancedBy(3), end: hex.startIndex.advancedBy(5))
    let blueRange   = Range<String.Index>(start: hex.startIndex.advancedBy(5), end: hex.startIndex.advancedBy(7))

    var red     : UInt32 = 0
    var green   : UInt32 = 0
    var blue    : UInt32 = 0

    NSScanner(string: hex.substringWithRange(redRange)).scanHexInt(&red)
    NSScanner(string: hex.substringWithRange(greenRange)).scanHexInt(&green)
    NSScanner(string: hex.substringWithRange(blueRange)).scanHexInt(&blue)

    self.init(
      red: CGFloat(red) / 255,
      green: CGFloat(green) / 255,
      blue: CGFloat(blue) / 255,
      alpha: 1
    )
  }
}

斯威夫特的版本。作为函数或扩展使用。

Function

  func UIColorFromRGB(colorCode: String, alpha: Float = 1.0) -> UIColor{
    var scanner = NSScanner(string:colorCode)
    var color:UInt32 = 0;
    scanner.scanHexInt(&color)
    
    let mask = 0x000000FF
    let r = CGFloat(Float(Int(color >> 16) & mask)/255.0)
    let g = CGFloat(Float(Int(color >> 8) & mask)/255.0)
    let b = CGFloat(Float(Int(color) & mask)/255.0)
    
    return UIColor(red: r, green: g, blue: b, alpha: CGFloat(alpha))
}

Extension

extension UIColor {
    convenience init(colorCode: String, alpha: Float = 1.0){
        var scanner = NSScanner(string:colorCode)
        var color:UInt32 = 0;
        scanner.scanHexInt(&color)
        
        let mask = 0x000000FF
        let r = CGFloat(Float(Int(color >> 16) & mask)/255.0)
        let g = CGFloat(Float(Int(color >> 8) & mask)/255.0)
        let b = CGFloat(Float(Int(color) & mask)/255.0)
        
        self.init(red: r, green: g, blue: b, alpha: CGFloat(alpha))
    }
}

How to call

let hexColorFromFunction = UIColorFromRGB("F4C124", alpha: 1.0)
let hexColorFromExtension = UIColor(colorCode: "F4C124", alpha: 1.0)

You can also define your Hex Color from interface builder.

使用任何转换器网站将十六进制颜色转换为RGB值(如果你谷歌“十六进制到RGB”，你会看到一吨)。例如，这个:http://www.rgbtohex.net/hextorgb/

然后将颜色属性更改为UIColor。例子:

self.profilePicture.layer.borderColor = [UIColor colorWithRed:0 green:167 blue:142 alpha:1.0].CGColor;

十六进制颜色值是:00a78e转换为RGB: R: 0 G: 167 B: 142

如果你给出的RGB值不在0到1.0之间，你必须将它们除以255。例子:

self.profilePicture.layer.borderColor = [UIColor colorWithRed:83.00/255.0 green:123.00/255.0 blue:53.00/255.0 alpha:1.0].CGColor; 

斯威夫特版本:

extension UIColor {
    convenience init?(var hex: String) {
        hex = hex.stringByTrimmingCharactersInSet(NSCharacterSet.whitespaceAndNewlineCharacterSet()).uppercaseString
        hex = (hex.hasPrefix("#")) ? hex.substringFromIndex(advance(hex.startIndex, 1)) : hex

        var value: UInt32 = 0
        if NSScanner(string: hex).scanHexInt(&value) {
            if count(hex) == 8 {
                self.init(red: CGFloat((value & 0xFF000000) >> 24) / 255.0,
                    green: CGFloat((value & 0x00FF0000) >> 16) / 255.0,
                    blue: CGFloat((value & 0x0000FF00) >> 8) / 255.0,
                    alpha: CGFloat((value & 0x000000FF)) / 255.0)
                return
            } else if count(hex) == 6 {
                self.init(red: CGFloat((value & 0xFF0000) >> 16) / 255.0,
                    green: CGFloat((value & 0x00FF00) >> 8) / 255.0,
                    blue: CGFloat(value & 0x0000FF) / 255.0,
                    alpha: 1.0)
                return
            }
        }
        self.init()
        return nil
    }
}