Fish do indeed perceive color. Every fly fisher knows that or ought to know that. Like humans, the retina of a fish have rods and cones. Cones are used in the day and rods at night. Color vision evolved to help fish identify potential food. In the environment of the fish, the background will either be the bottom, the water itself, or if looking up for food it could be the sky. The bottom is normally tannish olive to green. When looking across the water, the background appears pale silver blue. But if the water is off color due to algae or high water one must take that into consideration as well. Skylight becomes more important at dusk and dawn when it contains more reds.

Thus for opportunistically feeding game fish, flies with bright or contrasting colors and/or a lot of flash will make them stand out against the above mentioned backgrounds. The Mickey Finn, tied with yellow and red, and a silver body is one of the most effective attractor patterns. As for dry fly attractors , the Royal Wulff is still hard to beat, with its red and peacock body and white wings. Black flies, because of their strong silhouette also are easy for fish to spot. Let