I discovered (by asking dumb questions) that if I sponge/hose the sweat off my black horse, she doesn't fade as much. If I just turn her out, over time, she will start to turn sort of red in the saddle and girth area from the sweat bleaching the hair.
I also will clean her eyes nose and ears if we have been riding in wooded areas. Just to clear any spiders/webs and ticks off. I have to do the same to myself