There it was:
Douglas talking about Context Highlighting (Coloring)http://www.youtube.com/watch?v=b0EF0VTs ... page#t=900
Probably, it's easy to color functions, but hard to detect the right level or variables. Probably (I hope) I'm wrong with it.
Wowowow. Guys. I forgot to talk about what I'm thinking. And i thinking it should be a Switch with a hot key. Eventually, if it will be a Key that instantly switches highlighting when I holding key pressed and switched back when I release it. It should be brilliant useful thing for almost any modern functional language developers.