from_html (Color::RGB)

    # File lib/color/rgb.rb, line 48
        def from_html(html_colour)
          html_colour = html_colour.gsub(%r{[#;]}, '')
          case html_colour.size
          when 3
            colours = html_colour.scan(%r{[0-9A-Fa-f]}).map { |el| (el * 2).to_i(16) }
          when 6
            colours = html_colour.scan(%r<[0-9A-Fa-f]{2}>).map { |el| el.to_i(16) }
          else
            raise ArgumentError
          end

          Color::RGB.new(*colours)
        end