So from a legal stand point on motor vehicles (not talking about emergency vehicle work lights), Amber is front and Red is rear. Much like the rear facing fog lights from Europe that are very much needed in dense fog. If an amber light is used it can confuse the driver who is coming up on you and think that they are getting ready to have a head-on collision. Amber is used only for fog/snow/ice in the front and turn signals front & rear. White is used for headlights, DRL's, and backup lights. Red is used for tail, brake and rear fog lights. The problem today is everybody does what they want and now we see a rainbow of colored lights facing every which way and if the Police want to pull you over and give out tickets for unauthorized lights they can & will.