class NSString

  # @return [UIColor]
  def uicolor(alpha=nil)
    if self[0,1] == '#'
      if self.length == 4
        return (self[1] * 2 + self[2] * 2 + self[3] * 2).to_i(16).uicolor(alpha)
      end
      return self[1..-1].to_i(16).uicolor(alpha)
    end

    img = UIImage.imageNamed(self)
    img && img.uicolor(alpha)
  end

  def cgcolor(alpha=nil)
    uicolor(alpha).CGColor
  end

  def skcolor(alpha=nil)
    uicolor(alpha)
  end

end