task :test do
  [some preparatory stuff]
  test_stream "rake parallel:spec 2>&1", :colorize => true
end
def test_stream(command, options = {})
  invoke_command(command) do |ch, stream, out| 
    trap("INT") { puts 'Interrupted'; exit 0; } 
    if options[:colorize]
      out.gsub!(/(?<= ^|[\.F*] ) \. (?= $|[\.F*] )/x, "\\033[32m.\\033[0m") # green
      out.gsub!(/(?<= ^|[\.F*] )  F (?= $|[\.F*] )/x, "\\033[31mF\\033[0m") # red
      out.gsub!(/(?<= ^|[\.F*] ) \* (?= $|[\.F*] )/x, "\\033[33m*\\033[0m") # orange
    end  
    print out
  end  
end