Dogs · Myth check · Verdict: Not supported
Dogs only see in black and white
Gilbert JonesResearch summary · sources below · Reviewed October 17, 2026Bottom line: Not true. Dogs see colour, just fewer colours than we do. They see blues and yellows well, while reds and greens look dull, greyish or brownish to them.
Where the myth came from
In the 1940s, an influential book on animal eyes suggested dogs could barely see colour, if at all. The idea stuck for decades.
What the research found
In 1989, researchers at the University of California, Santa Barbara tested dogs with colour-matching tasks. They found that dogs have two types of colour-sensing cells (cones) in their eyes, where people usually have three. That means dogs have “dichromatic” colour vision, similar to a person with red-green colour blindness.
- Blues and yellows: dogs see these clearly
- Reds and greens: these look muted, often greyish or brownish
What it means for your dog
- A red ball on green grass can be hard for a dog to spot. A blue or yellow toy stands out much better.
- Dogs lean heavily on smell, movement and brightness, not just colour, so they still find most things fine.
What the evidence says
Dogs see only in black and white
Not supported evidenceColour-matching experiments showed dogs can tell colours apart.
Sources: cambridge.org
Dogs have two-colour (dichromatic) vision, seeing blues and yellows best
Strong evidenceShown by behavioural tests in 1989 and consistent with what is known about the dog retina. The original study tested only three dogs, but later work agrees.
Sources: cambridge.org · scientificamerican.com
This note shares experience and research, not a diagnosis. If your pet seems unwell, contact a vet.
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