I've long felt this whole concept is a waste of time. I've been using a very simple rule since shortly after I started programming: comments are green. That's it. That's the rule. Distinguish code from stuff that isn't code, and otherwise just read the damn thing. No highlighting at all would be fine too. Playing games with rainbows makes everything take more effort to read, not less. You ever notice how you do just fine parsing syntax intuitively and subconsciously as, for example, you're reading this paragraph? We already spend our entire lives training the skill of instantly understanding syntax when reading un-highlighted text.