I can't quite help you with your question directly (I just print from
Textmate -- not colour coded), but for those of you looking to print
code in their Wordpress powered blogs, I've been using Code Snippet
(http://blog.enargi.com/codesnippet/).  Although it doesn't officially
support Ruby, if you move Ruby script from the Geshi folder (a required
dependency) into your Code Snippet directory, you'll be made in the
shade.

James Herdman