Print out to the console terminal's 256 width colors.

256_colors.rb

#!/usr/bin/env ruby
# This prints to the console 256 colors for foreground & background

%w(38 48).each do |fgbg| # Foreground/Background
  (0..256).each do |color|
    print "\e[#{fgbg};5;#{color}m" + " #{color}".ljust(8, ' ') + "\e[0m"
    print "\n" if (color + 1) % 10 == 0
  end
  print "\n\n"
end