$ sudo gem install colored
Launch yourself an irb and try ‘er out:
Fun stuff (pretend it says colored, not color for the require). Not just for the console, though—it also works in Rails log files.
logger.debug "API: ".red.bold + "Got topics from Chowhound.".red
And hey, Windows users?
$ gem install win32console
Here’s a short screencast (it’s so fast that it appears static):