red-green.png

ruby-toptal-tip.rb

# Ruby has great gems for coloring print to terminal,
# but sometimes you just need to print a couple of times and
# don't want to add another gem just for that.

# For example, instead of:
puts "\e[31mThis is red!\e[0m"
puts "\e[32mThis is green!\e[0m"

# reopen the String class and add all the colors you need:
class String
  def red
    "\e[31m#{self}\e[0m"
  end
  
  def green
    "\e[32m#{self}\e[0m"
  end
end

# and then use them!
puts "Red again!".red
puts "Green again!".green
puts "Mixed %s with %s!" % ["red".red, "green".green]

# Other example:
a = 2
b = 3
format = "%s + %s = %s"
puts format % [a.to_s.red, b.to_s.red, (a + b).to_s.green]

# instead of the unreadable code:
puts "\e[31m#{a}\e[0m + \e[31m#{b}\e[0m = \e[32m#{sum}\e[0m"

I updated my code with alternative solutions based on yours.
https://gist.github.com/neves/f9602ddd8653d03167f2