Imagine a curtain, and two strings. Pulling one string brings it down, pulling the other brings it up. Usually in office environments, these two strings are the same color and this makes it so users pull the wrong string 50% of the time.
Any color ideas for these strings to illustrate Up and Down, if there are any? I'm aware that just giving them two different colors would solve the problem once the user learns which one does what thing, but any way to help a first time user?