Animal Color Vision: What Animals Really See

Species explorer

How does each animal see color?

Start with the number of cone types. Select a vision system to compare the animals that use it, then open the complete table for every species and caveat.

Want the long version for dogs specifically? Read are dogs color blind?

What animals are color blind?

It depends what you mean by color blind. If it means seeing no color at all, very few animals qualify: sharks, whales, dolphins, seals and a handful of deep-sea species that carry a single cone type. If it means seeing fewer colors than a human — the way "color blind" is used about people — then most mammals qualify, because most mammals have two cone types rather than three.

That is the key fact behind almost every question in this list. Early mammals were small and nocturnal, and in the dark colour vision is worth less than sensitivity to dim light. Two cone types survived; the third was lost. Primates later re-evolved a third cone, which is why humans, apes and Old World monkeys stand out among mammals rather than representing the norm.

So the honest summary is that dogs, cats, horses, cows, deer and rabbits are not colour blind in the sense of seeing grey. They see a real, functioning blue-yellow world. What they lack is the red-green separation humans take for granted — the same axis that is missing in the most common form of human colour vision deficiency.

What does a dichromatic animal actually see?

A dichromat has two cone signals to compare instead of three. Everything it sees is built from that one comparison, so the visible spectrum folds down to roughly two colour families — blue on one side, yellow on the other — meeting at a neutral grey point in the middle. Wavelengths that a human calls red, orange, yellow and green all land somewhere in the yellow half, which is why they blur together.

The practical consequences are strange and specific. A red ball on green grass is nearly invisible to a dog, not because it is dark but because the two land in the same colour bin; the dog finds it by shape, movement and smell instead. Blaze orange, worn by hunters precisely so other people can see it, reads to a deer as a dull yellowish grey against foliage. And a bull's reaction to a matador's cape has nothing to do with red — cattle are dichromats, and it is the movement that triggers the charge.

None of this makes dichromatic vision poor. Dogs and deer beat humans easily on motion detection and low-light sensitivity. Colour is one channel among several, and evolution has spent it differently in different species.

Which animals see more colors than humans?

Birds are the headline case. Most have four cone types instead of three, including one sensitive to ultraviolet or violet, and each cone sits behind a coloured oil droplet that narrows its response and sharpens discrimination further. The result is a colour space humans cannot picture: plumage that looks plain brown to us can carry bright UV patterning that other birds read at a glance.

Many fish and reptiles are tetrachromatic too, and insects run on a spectrum shifted toward the short end. A honey bee is trichromatic like us, but its three receptors are tuned to ultraviolet, blue and green — so it sees UV nectar guides painted across flower petals, and red looks black to it.

The mantis shrimp is the famous twist. It carries twelve to sixteen photoreceptor types, more than any other known animal, and was long assumed to have unimaginably rich colour vision. Behavioural testing found the opposite: it discriminates between similar colours worse than a human does. The current explanation is that it does not compare receptor signals the way our brains do, but recognises colours directly — trading precision for speed.

Do animals have the same color blindness as people?

The mechanism is comparable, which is why the comparison is useful. A human with deuteranopia and a dog both work from two cone signals rather than three, and both lose the same red-green axis. Simulations of dog vision and simulations of human deuteranopia look very similar for exactly that reason.

The difference is that in a dog this is the normal, fully adapted state, not a deficiency. Its retina, its brain, and its behaviour are all built around it, and other senses carry more of the load. In a human, red-green deficiency sits inside a world designed by trichromats — traffic lights, wiring diagrams, colour-coded charts and maps — which is what makes it inconvenient rather than merely different.

If you are curious how the two compare directly, our screening estimates your own colour vision, and the filter tool can show you what a red-green deficient view of a photo looks like.

Animal color vision — frequently asked questions

What animals are color blind?

In the strict sense of seeing no color at all, very few: sharks, whales, dolphins and seals carry a single cone type. In the looser sense of seeing fewer colors than humans, most mammals qualify — dogs, cats, horses, cattle, deer, rabbits, squirrels and many others are dichromats with two cone types, giving them vision close to human red-green color blindness.

Are dogs color blind?

Not in the sense of seeing only grey. Dogs are dichromats with two cone types, so they see blues and yellows clearly but cannot separate red from green — close to human deuteranopia. A red ball on green grass is genuinely hard for a dog to spot by color alone.

Are bulls really angered by the color red?

No. Cattle are dichromats and do not see red as red at all. What provokes a charge in a bullring is the movement of the cape, not its color — the same cape moved the same way in any color produces the same reaction.

Are deer color blind?

Deer are dichromats with strong sensitivity at the short-wavelength end. They see blues vividly and cannot separate red from green, which is why blaze orange — highly visible to humans — reads to a deer as a dull yellowish grey. Blue clothing and UV-brightened fabrics stand out to them far more.

Which animals see the most colors?

Birds are the strongest all-round case: four cone types including ultraviolet, sharpened by colored oil droplets. Many fish and reptiles are tetrachromatic too. The mantis shrimp has the most photoreceptor types of any known animal at twelve to sixteen, but behavioural tests show it discriminates colors worse than humans do.

Are cats color blind?

Cats are dichromats, like dogs. They see blues and greens but have poor red discrimination and less color saturation overall. Their eyes are built for low light and motion rather than color, which suits a crepuscular hunter.

Why are most mammals color blind?

Early mammals were small and nocturnal, and in dim light sensitivity matters more than color. Two of the ancestral cone types were lost, leaving most mammals dichromatic. Primates later re-evolved a third cone, which is why humans, apes and Old World monkeys are unusual among mammals rather than typical.