Lasseter was learning: If he reached out to the technologists, the technologists would reach back.
....
As the work progressed, one of the team members...voiced concern about lasseter's color choices. Lasseter wanted purple leaves on the trees. Leves aren't purple, the staffer objected. Indeed, the group had been studying magazine photos of trees for reference and they seemed to back up this observation.
Rather than simply asserting his artistic authority, Lasseter took the group to a San Francisco museum exhibit of paintings by the illustrator Maxfield Parrish, noted for his rich use of light in natural scenes. After a while, the dissenter volunteered that Lasseter was right: Leaves could be purple. It all depende on the light. Lasseter had showed the group that there was more to realism than was dreamt of in their technical papers.
David A. Price, The Pixar Touch: The Making of a Company, Vintage Books, 2009, p. 56.
