Fun Fact du Jour: What colors can dogs and cats see?

Can Fido and Fluffy really tell that their food dish is blue and their water dish is pink? Or is it a classic fault to chalk up to anthropomorphism?

A) Characteristics of feline vision:

(Image source: http://meathaus.com/2008/11/24/celia-bullwinkel-cat-drawings/)
-Wikipedia article "Cat"

"...domestic cats have rather poor color vision and (like most non-primate mammals) have only two types of cones, optimized for sensitivity to blue and yellowish green; they have limited ability to distinguish between red and green,^[71] although they can achieve this in some conditions."

Conclusions:
-So they can see blue and yellowish green. However they aren't good at telling the difference between red and green.
-However they have really good night vision (same Wiki article):

Good for cats:

(aka night vision)

Bad for cats:

(from brickartist.com. A gallery of lego art - pretty cool!) &

" Cats have excellent night vision and can see at only one-sixth the light level required for human vision."

soo cool!
so that's why my cat wants to play in the dark...

B) What is canine vision like?

-Wikipedia article "Dog"

"Like most mammals, dogs aredichromats and have color vision equivalent to red-green color blindness in humans (deuteranopia).^[106]^[107]^[108]^[109]Dogs are less sensitive to differences in grey shades than humans and also can detect brightness at about half the accuracy of humans.^[110]

The dog's visual system has evolved to aid proficient hunting.^[106] While a dog's visual acuity is poor (that of a poodle's has been estimated to translate to a Snellen rating of 20/75^[106]), their visual discrimination for moving objects is very high; dogs have been shown to be able to discriminate between humans (e.g., identifying their owner) at a range of between 800 and 900 m, however this range decreases to 500–600 m if the object is stationary.^[106]

Dogs have a temporal resolution of between 60 and 70 Hz, which explains why many dogs struggle to watch television, as most such modern screens are optimized for humans at 50–60 Hz.^[110] Dogs can detect a change in movement that exists in a single diopter of space within their eye. Humans, by comparison, require a change of between 10 and 20 diopters to detect movement.^[111]^[112]

As crepuscular hunters, dogs often rely on their vision in low light situations: They have very large pupils, a high density of rods in the fovea, an increased flicker rate, and a tapetum lucidum.^[106] The tapetum is a reflective surface behind the retina that reflects light to give the photoreceptors a second chance to catch the photons. There is also a relationship between body size and overall diameter of the eye. A range of 9.5 and 11.6 mm can be found between various breeds of dogs. This 20% variance can be substantial and is associated as an adaptation toward superior night vision.^[113]"

-So both dogs and cats can't tell the difference between red and green, and they have good night vision, definitely better than humans'. In addition, a dog's vision is also very good at detecting motion, which is good evolutionarily for hunting.

Good for dogs: