Massimo Verona created this fantastic Autumn Creek render as an exercise with the Forest Color map. He created nearly everything in the scene from scratch with the exception of a couple of trees, and the logs and large rock which are from Megascans. The water is simulated with Phoenix FD for a few frames, the small foam patches are added with Phoenix FD foam tex, GrowFX was used for the plants and of course V-Ray 3.5 for rendering.
Forest Color is a really handy map to create variations on trees. Not only variations per tree, but within the tree itself by colouring clusters of leaves just like you see in nature.