A simple script to colorize logs piped through it.

colorize.rb

#!/usr/bin/env ruby
require 'rubygems'
require 'term/ansicolor'

ARGF.each_line do |line|
  color = case line
          when /^ERROR/ then Term::ANSIColor.red
          when /^WARN/  then Term::ANSIColor.yellow
          when /^INFO/  then Term::ANSIColor.green
          else ""
          end

  STDOUT.write(color + line + Term::ANSIColor.reset)
end