How Fish See Color
“Colors are for fishermen,” the tackle shop proprietor said. “Fish don’t care.” Not to be deterred, I scrutinized a giant rack of Wiggle-Warts: tiger-striped, two-tone, pearlescent, UV-enhanced. More shades than a 64-pack of Crayolas.
So why do you fancy certain colors? Is it because they catch your eye or because they catch fish? Let’s consider the properties of light transmission in water before we get into the more complicated subject of how colors attract fish.
Light is attenuated when it enters water due to scattering and absorption. Red and orange, wavelengths with lower photon energy, penetrate water less than blue and violet. The depth of water, fish location and the amount of suspended material or turbidity also affect color properties. If water attenuates or filters out a color, the object will appear gray or black. That much we know. However, in the case of what fish see, there is more than what meets the eye.
According to Jason Randall, author of “Trout Sense,” the ovoid shape of the trout eye allows it to see nearsighted directly in front of its nose and farsighted laterally. Having eyes in the side of the head expands their field of vision. The limit of useful vision in turbid rivers and lakes, however, is likely no more than 3 to 6 feet, whereas fish might see objects up to 100 feet away in clear oceanic waters.
Similar to humans, the fish retina is made up of rod and cone cells that allow them to see light and color, respectively. Most fish can distinguish color over wavelengths ranging from UV to red although freshwater fishes operate within a narrow range depending on whether they operate as a shallow water predator or a deep-water bottom-feeder, for example.
Fish that are active during the day tend to have large eyes that help them search for prey. In contrast, beady-eyed nocturnal feeders, such as catfish, are more dependent on chemical senses. There’s more. Walleye, sharks and sturgeons have a special light-gathering layer of tissue in the eye, the “tapetum lucidum,” that helps them see during low light periods of dawn and dusk. The eyes of these fishes shine, as do those of cats.
Knowing that the fish eyes allow for clearly focused images, contrast-detection and color recognition over a range of environmental conditions, how do you match the colors of the rainbow (or not) to attract more fish?
Choosing the right lure or fly requires understanding how images reach the fish’s brain and what triggers a strike. Color choice is most important for a fly fisher trying to mimic what a fish would choose to eat. The size and profile of your fly should also match items in their diet. Knowing that cones can only operate at high light intensities and rods take on more importance as light fades, you might add a “hot spot” or fluorescent accent to a dark fly for contrast. A fluorescent color having longer wavelengths than the color of the water will provide better long-distance visibility.
To increase visibility of plugs and spinners, gear anglers might offer a tiger-stripe pattern, for example black over red or blue and silver. Red-and-white Daredevil spoons are iconic for more reasons than they are pretty to look at. They provide contrast. When selecting lure color, note that dark purple or blue is visible at deeper depth (and with distance from a fish) than red or orange. Chartreuse seems to work well in cloudy or turbid water. Interestingly, black is the most visible color in nearly all settings.
Proven lures provide both motion and contrast. Offerings that reflect light and appear lighter or darker than the background should also be favored. In the end, it may not be that a specific color attracts, but proper presentation. To hook more fish place your offering within a fish’s field of view in a manner that triggers feeding or aggressive behavior.
Dennis Dauble is the author of the award-winning “Fishes of the Columbia Basin” and “The Barbless Hook”.