In The Matrix, you could tell which "world" you're in by the general grade of color. When in the Matrix, everything had a greenish overtone, and when in the "real world" it was more blue. I really liked that use of color to be a part of the story telling process.
It's not a great film from a storytelling perspective, but I think Beyond the Black Rainbow is a fantastic example of this sort of use of color
One of the few times I think I prefer watching the trailer to the movie.