Color blind or not - they can tell dark from light. (like on a black and white movie, you can tell that people are wearing different color clothes).
Red - back when I worked at the riding stable, I would stash my gloves in a bag in the closet so that I could smell the horses during the few winter months that they were closed.
@ninnymary - did you know that they are usually born dark and gradually lighten up as they grow?
Some of them stay dark - which is still LOVELY!
And - like other superstars - they are only magnificent while on stage. Otherwise, they scratch their butts just like any other horse.
Whenever they needed it. Usually 2 or 3 times during the summer and one time just before winter set in. I used Murphey's Oil soap. Smelled good, didn't irritate their skin. Use it on the dogs too.