Do Dogs and Cats Really Only See in Black and White? The Truth About Their Colour Vision
, by Michael van Wassem, 6 min reading time
Do dogs and cats really see everything in black and white? No. Discover how their colour vision actually works and why toy colour matters.
You have probably heard it before: dogs and cats are said to see the world in black and white, like an old film without colour. It is one of the most persistent myths about pets — and it is not true. Dogs and cats do see colour, just differently from us. In this article you will read how their colour vision actually works, which colours they can and cannot tell apart, and what this means in practice, for example for the colour of their toys.
Can dogs and cats see colour? The short answer
No, dogs and cats do not see in black and white. They do have more limited colour vision than people. While most humans are trichromats (three types of colour receptors in the eye), dogs and cats are dichromats: they only have two. As a result, they see the world roughly the way a person with red-green colour blindness does. They can tell blue and yellow apart well, but red and green both appear to them as a kind of yellowish-brown or greyish tone.
How does your dog's or cat's eye work?
The retina contains two types of light-sensitive cells: rods and cones. Rods provide vision in low light and detect movement, while cones are responsible for colour vision and sharpness in daylight. Humans usually have three types of cones, sensitive to red, green and blue light. Dogs and cats only have two: one type that mainly picks up blue-violet light, and one type sensitive to yellow-green light. Red falls largely outside their range.
Dogs and cats also have proportionally far more rods than cones in their retina. This is a deliberate trade-off by nature: less colour discrimination, but much better vision in dim light and darkness — exactly what a hunting predator needs.
Which colours can dogs and cats see well, and which not?
Behavioural studies in dogs, including tests where dogs had to choose between coloured cards, show that they can best distinguish between:
- Blue and yellow — they see these colours clearly separated from one another.
- Shades of grey — they pick up differences in brightness well, even without a colour difference.
Harder for them:
- Red — they likely see this as a dark, greyish-brown colour.
- Green — this visually blends with yellow and orange into roughly the same tone.
- The difference between red and green — for a dog or cat these are almost the same colour.
Less research has been done on cats than on dogs, but the structure of the cat's eye is similar: they too have two types of cones and see the world mainly in blue, yellow and grey tones.
Where does the black-and-white myth come from?
The idea that dogs only see in black and white dates back to the early twentieth century. Scientists already knew back then that the retina of dogs and cats contains many rods and relatively few cones, and drew the premature conclusion that colour vision was almost entirely absent in them. It was only from the 1980s onwards, with targeted behavioural studies in dogs, that it became clear they do in fact distinguish colours — just fewer than humans. The myth stuck around anyway, partly because it is so easy to remember.
What do dogs and cats see better than we do?
Their more limited colour vision is more than compensated for by other visual advantages:
- Night vision: thanks to the tapetum lucidum, a reflective layer behind the retina, dogs and especially cats can see far better in low light than we can. This is also why their eyes appear to "glow" at night in the light of a lamp or camera flash.
- Motion detection: because of the high number of rods, they are extremely sensitive to movement, even at the edge of their field of view.
- Wider field of view: in most dogs and cats the eyes sit slightly more to the sides, giving a larger overall field of view than humans have — though this comes at the cost of depth perception straight ahead.
What they are less good at than us: focusing on things close up and picking out fine detail at a distance. Their visual acuity is considerably lower than that of a person with good eyesight.
In practice: why toy colour actually matters
This is more than a fun fact — it has direct practical consequences. A red ball on the grass is nearly impossible for a dog to find: red and green blend together for them into the same greyish-brown tone. The same applies to orange toys on a wooden floor, or a red toy in a red cat bed.
So choose toys in blue or yellow where possible: these colours stand out clearly for your dog or cat, regardless of the background. A good example is the KONG Floppy Knots Hippo for dogs. For cats, the KONG Connects Magnicat is a great option too: its unpredictable, darting movement appeals to a cat's hunting instinct, regardless of colour.
Frequently asked questions about colour vision in pets
Do all dog and cat breeds see the same way?
As far as is known, there is no proven difference in colour vision between breeds. The structure of the retina is essentially the same in nearly all dogs and cats.
Does colour vision get worse with age?
As in humans, overall visual acuity can decline in older animals, for example due to cataracts. This is different from the number of colours they can naturally distinguish.
Do rabbits, birds or fish see the same way?
No, this varies greatly between species. Birds, for example, are often tetrachromats (four types of cones) and can see even more colours than humans, including ultraviolet light. Rodents such as rabbits have yet another type of dichromatic vision.
So does colour not matter at all when choosing toys?
Colour is one factor, but scent, sound, texture and especially movement play at least as big a role in how appealing a dog or cat finds a toy.
Summary
Dogs and cats do not see in black and white, but they do see fewer colours than humans. They are dichromats that can distinguish blue and yellow well, while red and green look roughly the same greyish-brown tone to them. What they lack in colour vision, they more than make up for with superior night vision, a wider field of view and an excellent ability to detect movement. For you as an owner, this comes down to one practical takeaway: choose toys in blue or yellow, so they really stand out for your pet.
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