While project viewer is great, if you have more than one project open (e.g., docs/code) it becames hard to keep context.
Making color of files/projects user selectable would be great (e.g., I assign blue to the docs project, and green to some other code project)
The more GUI customizability we have, the better. I picked this from onenote, where notebooks get funny colors automatically. Looks silly, but it's immensely useful to know where you are ('I was editing something blue')...
Another case of something that probably won't happen unless I get a patch from someone.