It would be really useful to have the ability to color code the nodes in the apex editor somewhat, to make it easier to read what is what at a glance. Preferably something we could set from code, that enums and such could take part in decide what color should be displayed. I particularly would benefit from this on Selectors.
I have logged in our backlog as a feature request, since I agree that it would be handy to be able to utilize more color coding. However, I cannot say when or if we will get around to implementing this feature.