swift 颜色设置方法

如下：

func RGB(red: CGFloat, green: CGFloat, blue: CGFloat) -> UIColor {

   return UIColor.init(red: red / 255.0, green: green / 255.0, blue: blue / 255.0, alpha: 1.0)
}

func RGB(red: CGFloat, green: CGFloat, blue: CGFloat, alpha: CGFloat) -> UIColor {

    return UIColor.init(red: red / 255.0, green: green / 255.0, blue: blue / 255.0, alpha: alpha)
}

func ColorFromHex(rgbValue: Int) -> (UIColor) {

    return UIColor(red: ((CGFloat)((rgbValue & 0xFF0000) >> 16)) / 255.0,
                   green: ((CGFloat)((rgbValue & 0xFF00) >> 8)) / 255.0,
                   blue: ((CGFloat)(rgbValue & 0xFF)) / 255.0,alpha: 1.0)
}

func ColorFromHex(rgbValue: Int, alpha: CGFloat) -> (UIColor) {

    return UIColor(red: ((CGFloat)((rgbValue & 0xFF0000) >> 16)) / 255.0,
                   green: ((CGFloat)((rgbValue & 0xFF00) >> 8)) / 255.0,
                   blue: ((CGFloat)(rgbValue & 0xFF)) / 255.0,alpha: alpha)
}