# File lib/test/unit/color.rb, line 11
        def parse_256_color(string)
          case string
          when /\A([0-5])([0-5])([0-5])\z/
            red, green, blue = $1, $2, $3
            red.to_i * 36 + green.to_i * 6 + blue.to_i + 16
          else
            message = "must be 'RGB' format and R, G and B " +
              "are in 0-5: #{string.inspect}"
            raise ParseError, message
          end
        end