string.colorize.rb

class String
  # ANSI-colored version of the string
  def colorize(color)
    n = case color
      when :black:   30
      when :red:     31
      when :green:   32
      when :yellow:  33
      when :blue:    34
      when :magenta: 35
      when :cyan:    36
      when :white:   37
      else return self
    end
    "\033[#{n}m#{self}\033[0m"
  end
end