Ruby : Printing colored character in Ruby: Colorize

Normally for web developer you dont need to know how to colorize the output in ruby, however if you are building some gem and you need to prompt User something beautifully then it might strike on your mind that “it would have been great; if it printed colored text”.

Moreover, you might also want to display the output of rake tasks you create in your app in colored  format.


Ruby String class extension. Adds methods to set text color, background color and, text effects on ruby console and command line output, using ANSI escape sequences.


sudo gem install colorize


puts "This is blue".colorize(:blue)
puts "This is light blue".colorize(:light_blue)
puts "This is also blue".colorize(:color => :blue)
puts "This is light blue with red background".colorize(:color => :light_blue, :background => :red)
puts "This is light blue with red background".colorize(:light_blue ).colorize( :background => :red)
puts "This is blue text on red".blue.on_red
puts "This is red on blue".colorize(:red).on_blue
puts "This is red on blue and underline".colorize(:red).on_blue.underline
puts "This is blue text on red".blue.on_red.blink
puts "This is uncolorized".blue.on_red.uncolorize

Simply Tweak String base class

class String
  def black; "\e[30m#{self}\e[0m" end
  def red; "\e[31m#{self}\e[0m" end
  def green; "\e[32m#{self}\e[0m" end
  def brown; "\e[33m#{self}\e[0m" end
  def blue; "\e[34m#{self}\e[0m" end
  def magenta; "\e[35m#{self}\e[0m" end
  def cyan; "\e[36m#{self}\e[0m" end
  def gray; "\e[37m#{self}\e[0m" end

  def bg_black; "\e[40m#{self}\e[0m" end
  def bg_red; "\e[41m#{self}\e[0m" end
  def bg_green; "\e[42m#{self}\e[0m" end
  def bg_brown; "\e[43m#{self}\e[0m" end
  def bg_blue; "\e[44m#{self}\e[0m" end
  def bg_magenta; "\e[45m#{self}\e[0m" end
  def bg_cyan; "\e[46m#{self}\e[0m" end
  def bg_gray; "\e[47m#{self}\e[0m" end

  def bold; "\e[1m#{self}\e[22m" end
  def italic; "\e[3m#{self}\e[23m" end
  def underline; "\e[4m#{self}\e[24m" end
  def blink; "\e[5m#{self}\e[25m" end
  def reverse_color; "\e[7m#{self}\e[27m" end


"I'm back green".bg_green
puts "I'm red and back cyan".red.bg_cyan
puts "I'm bold and green and background red"

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