Let color accent your comic. Considering this isn't your full-time job, I don't think it's worth killing yourself by coloring every page, either. It's one thing if you have the time and the want. I've actually been reading a comic that is literally drawn as storyboard sketches, colored pages being far and few between, and I actually am completely fine with that.

Save all-color pages when you print the thing...if you want to make it expensive, anyway. XP