Trout fisherman often give away their presence to the fish by the equipment they are wearing. The yo-yo hanging on the fly fishing vest that attaches to the hemostats or line clippers is often plated with chrome, giving off flashes of light. Some fly boxes that you wear on the chest are also bright aluminum-not a good idea. I recently fished with a fellow who wore a bright yellow hat on a meadow stream in Pennsylvania. From 100 yards away you could see his every movement,-I'm sure that trout near him could, too.