I think we may have touched on this subject before, but it came up in conversation earlier today.
I've seen exit signs in America with both red and green lettering. I can't remember whether a specific color was all in one town or even one state, so are there local codes which specify which color is to be used?
Is there some other reason, e.g. red for exit corridors and green for the actual exit doors?
Or is it just a case of "Take your pick" ?