Notes - from The art of Monsters, inc

The colour script defines the mood of each scene in the film through the use of light, colour, and atmosphere.

That was somthing we definitely learned with Sullivan: It's pretty design a charater unless you know who he is. Otherwise, you don't have anything on which to hang your design. Like Sullivan, he was the most difficult to design because his part in the story changed many times as it evolved. So when we do our animation film, we need to know what is our character looks like; we need to know their characteristic; we need to think of our characters like a real person who stand near us.

There is this wonderful cycle of inspiration, traveling via drawings, betwwen the story and art departments, each inspiring the other.