What Colors do Fish Actually See?

And well, that’s it. That’s the joke.

With recent supply chain issues and the omnipresent digital shopping environment, a trip to your local sporting goods store is liable to yield a lure selection which at best might be considered a crapshoot. Or, just as likely, a disappointment.

Nonetheless, I still find myself yearning to walk into a well-stocked tackle shop, if for no other reason than to harken back to my youth in northern Wisconsin when I would spend literal hours in the fishing department of Rondeau’s Hardware Store. I’d gaze upon racks upon shelves upon racks of vibrant lure displays, yearning to make them all mine. I’d painstakingly try to decide where my hard-earned lemonade stand money would be spent.

Colors and “coolness” mattered a lot to 10-year-old me.

So began my informal education in fisheries biology, as well as business and marketing. In fact, many a fisherman could be bestowed with an honorary minor in marketing from the local boat launch community college. You don’t just go from calling white “white,” to calling it “pearl white,” to “Albino Rhino”—sure there are subtle differences, but do fish know the difference between white and pert-near white? Do fish care?

Acknowledging the standard cliché that lure colors options are daunting, MeatEater’s own Bent Podcast host Joe Cermele breaks down color options simply—lights, brights, and darks. That’s a good place to start. For anglers with an inclination to add nerdiness to their “tackle box” of nuance, we can examine fish physiology a bit deeper to understand fish vision, lure color, and situations when drawing upon said nerdiness might add greater success on the water.

It’s in the Water Generally speaking, fish eyes are similar to those of other vertebrates, including humans. Notably, however, because there is no air-to-cornea interface, fishes’ visual power is diminished by about 80% relative to terrestrial animals. Further, due to certain properties of an aqueous environment, water can be considered a more variable visual environment relative to how terrestrial organisms view the world. How much light and what colors are visible in water depends on conditions above, below, and at the water’s surface like cloud cover, ice, algae, suspended particulates, and vegetation.

Additionally, most fishes (aside from sharks) have pupils of a fixed diameter. This means that foraging success of species such as lake trout, which rely more heavily on visual acumen—their ability to see, track, and capture prey—is dependent on external conditions including light availability. These species physically change their location and depth to balance the risk-reward and energy output to capture prey. Their prey does the same. This is one reason why the crepuscular periods, dawn and dusk, are often most effective for anglers: prey and predators are overlapping in the water column based on light conditions and their ability to eat or not get eaten.

Obviously, light becomes less intense in deeper water, but changes to visible colors are not uniform across the color spectrum. On one end of the spectrum, reds and oranges are most readily absorbed in water, so these colors are most visible in shallow water. Darker blues and purples penetrate the deepest. Yellow and greens are in between.

When bass are shallow in spring, anglers often throw red crankbaits—not only will these “match the hatch” of typical crayfish prey in early season habitats and conditions, but from a visual perspective, that’s where those colored lures are most visible (in shallow water). Colors that show up better at depth, like blue, purple, or chartreuse, are often more popular for deep-diving crankbaits.

Of course, vision isn’t the only sensory system for fishes. The importance of vision and colors varies across species and life stages based on prey and habitat. The lateral line is critical for many species’ ability to detect and capture prey. If you’re trying to fish red and oranges too deep, you’d better hope the lure you’re tossing comes with dynamic action, rattles, and a lot of vibration.

UV Light vs. “Glow” Speaking of fishing at deeper depths, there’s often some confusion among anglers when it comes to the labeling and marketing of lures with “UV” and “glow-in-the-dark” colors. Some lures contain an ultraviolet coating, which reflects UV light. Humans cannot see light on that far end of the spectrum, but some fishes can. Depending on conditions, however, UV light may not penetrate deeply into the water column.

Other glow lures store light, which is often charged by UV light—essentially glow lures store and transport light to depths where light and colors would otherwise be absorbed before reaching those depths. Some lures contain both, and might be labeled as “UV-glow.”

With ice fishing conditions upon us in certain regions, layers of ice with snow cover dramatically decrease the amount of sunlight reaching below the surface. As such, UV colors alone will have minimal benefit, especially if you’re set up in a shanty to block out the elements, and thereby even more sunlight. However, glow colors can be especially effective through the ice. Species like burbot, which inhabit deep, dark, cold water throughout most of the year, are metabolically more effective in cold water and adapted to low light. Drop some glow down deep with some scent and they will likely investigate.

Interestingly, many salmon and trout species undergo a shift in their ability to detect UV light. During younger life stages, when trout are consuming high diet proportions of zooplankton, their eyes contain more UV-sensitive cones to be able to detect their plankton in shallow, open water. As they grow, their diet shifts towards consuming more fish and their need for UV sensitivity is lessened. The photoreceptors in their eyes change to be able to better forage at the depths with more prey fish.

A Colorful World From elementary school science classes to David Attenborough-narrated documentaries, there are extreme examples where fish have adapted their vision to the world they live in—bioluminescent fishes in the deep ocean, blind cave-dwelling fishes, even certain surface-dwelling fish in South America that have four pupils to see above and below the surface at the same instant. After hundreds of millions of years of selection and adaptations, this should be no surprise. But, aside from these extreme examples, understanding how fish see in the water—depending on relevant conditions, can be useful to anglers. Just as we adapt to changing conditions observed from the surface, fishes adapt to changing optical environments below the surface.

Does this mean you need every made-up color of the rainbow in your tackle box? Certainly not. Is it more fun that way? Maybe. Just don’t tell a 10-year old me.