The short answer is that color printing is unfortunately not supported for Visual Studio 2010. However, this is already on our list of features to reconsider during planning for the next release. If you'd like to vote for color printing
to be reinstated in a future version of VS, I'd encourage you to do so here. The more votes a bug gets, the more likely it is to be fixed in the future.
For now, you can potentially work around the absence of color printing by copying code into another application (e.g. MS Word) for printing. Visual Studio's RTF copy/paste functionality allows syntax coloring to persist when copying and pasting into
another rich text editor like Word, so copying/pasting from VS to Word and then printing from Word should allow you to print your code in color.
Brittany Behrens | Program Manager | Visual Studio Platform - Editor | The Visual Studio Blog | @VSEditor on Twitter