def color_chart
      [0, 1, 4, 5, 7].each do |attr|
        puts '----------------------------------------------------------------'
        puts "ESC[#{attr};Foreground;Background"
        30.upto(37) do |fg|
          40.upto(47) do |bg|
            print "\033[#{attr};#{fg};#{bg}m #{fg};#{bg}  "
          end
          puts "\033[0m"
        end
      end
    end
def color_chart
      [0, 1, 4, 5, 7].each do |attr|
        puts '----------------------------------------------------------------'
        puts "ESC[#{attr};Foreground;Background"
        30.upto(37) do |fg|
          40.upto(47) do |bg|
            print "\033[#{attr};#{fg};#{bg}m #{fg};#{bg}  "
          end
          puts "\033[0m"
        end
      end
    end
Displays a chart of all the possible ANSI foreground
 and background color combinations.
 @return [void]