Make color optional.

railties/lib/generators.rb

@@ -15,12 +15,20 @@ require 'generators/named_base'
 
 module Rails
   module Generators
+    # Remove builtin generators.
+    #
     def self.builtin
       Dir[File.dirname(__FILE__) + '/generators/*/*'].collect do |file|
         file.split('/')[-2, 2]
       end
     end
 
+    # Remove the color from output.
+    #
+    def self.no_color!
+      Thor::Base.shell = Thor::Shell::Basic
+    end
+
     # Receives a namespace and tries different combinations to find a generator.
     #
     # ==== Examples