Dogs see the world very differently than humans do. Their vision is dichromatic rather than trichromatic like humans, meaning they can only detect 2 primary colors – blue and yellow – compared to a human’s 3 – red, green, and blue.
Dog Vision Basics
This is why we often wonder how dogs perceive certain colors, like purple. To understand what purple looks like to dogs, we first have to understand some basics about how dog vision works:
- Dogs are essentially red-green colorblind. They cannot distinguish between red, orange, yellow, green, purple, brown, etc.
- They primarily see the blue and yellow spectrums, as well as brightness.
- Their eyes have rods for scotopic vision (nighttime) and less cones for photopic vision (daytime).
- They may perceive some reddish/purplish tones as a very dark gray or black due to their limited cones.
- Their visual acuity is 20/75 compared to a human’s 20/20.
Knowing this, we can make some predictions about how dogs see purple and other reddish/violet hues.
Does Purple Appear Gray or Black to Dogs?
Purple is a mix of red and blue light waves. Since dogs cannot detect red light waves very well, the red tones in purple are likely invisible or very dull to them.
This means dogs probably do not see the vibrant violet tones of purple. Instead, the color likely appears as a hazy bluish-gray color. Or, in darker purples with more red mixed in, the color may register as simply black.
In general, any hue made with a lot of red – like purple, pink, orange, brown – will look unsaturated and washed out, if visible at all.
| Color | How Humans See It | How Dogs Likely See It |
|---|---|---|
| Light purple | Vibrant violet | Hazy blue-gray |
| Dark purple | Deep violet | Dark gray or black |
| Lavender purple | Soft violet | Very light gray |
As the table shows, dogs miss out on the red tones that make purple look vibrant and saturated to our eyes.
Do Dogs Perceive Any Purple?
While dogs can’t see the true richness of purple, they may be able to perceive some element of the color.
Since dog vision sees the blue spectrum, they can detect the blue wavelengths in purple. However, without the red wavelengths, the color is not the bright violet humans see.
Think of it like this – humans see purple as its own distinct color between red and blue. Dogs, on the other hand, just see it as a variant of blue caused by very dull red tones.
So in essence, dogs do technically perceive purple, but only as a grayish, diluted version of blue. The red half of what makes purple “purple” is invisible to them.
Dog Vision vs. Human Vision
To fully understand why dogs see purple so differently, it helps to compare dog vision and human vision:
| Vision Feature | Human Eyes | Dog Eyes |
|---|---|---|
| Number of color receptors (cones) | 3 types detect red, green, blue | 2 types detect blue, green/yellow |
| Color spectrum seen | Red, green, blue | Blue, yellow |
| Rod cells for nightvision | Few rods, not very sensitive | High concentration of rods, very sensitive |
| Visual acuity | 20/20 is normal | 20/75 is normal |
As you can see, dogs have fewer cones tuned to fewer colors. Their vision trades vivid color for extreme night vision – which makes sense for canines evolved to hunt at dawn and dusk!
Other Colors Dogs Can’t See Well
Purple isn’t the only color dogs perceive differently. Dogs also can’t see red, orange, yellow, and green the way humans do.
Here is how other colors likely appear to dogs:
- Red: Very dark brown or black
- Orange: A muddy brown
- Yellow: A brighter brown
- Green: A muted blue or gray
Basically, any color with red tones will appear dark, dull or even black. Yellows may look brighter since dog eyes pick up more blue light than red.
Do Dog Toys Need to Be Purple?
Knowing dogs can’t see true purple, should dog toys even come in purple? Or do dogs perceive the color as just gray or black?
Just because dogs can’t see purple’s red tones doesn’t mean they can’t see the blue tones. So purple likely appears as a distinct color compared to gray or black objects, even if it seems muted to them.
Therefore, purple toys are still beneficial for dogs in these ways:
- The blue wavelengths make purple stand out from black, white, or gray toys.
- Light purple toys show up well against grass for outdoor fetching.
- Dark purple toys provide high contrast indoors.
So while purple doesn’t look the same, dogs can still perceive it as its own unique shade. Their vision is adapted to detect motion and contrasts rather than vibrant colors.
Do Dogs Dream in Color?
Since dogs see less color when awake, does that mean they also dream in black and white or muted colors?
Research indicates that dogs likely do dream in color. During sleep, the brain is activated in areas responsible for processing color. So even though they aren’t perceiving real colors, dogs’ brains recreate color in their dream state.
However, experts believe dogs probably don’t experience the same vibrant Technicolor that humans do. Their dreams are most likely muted versions of color similar to their waking experience.
So while dogs don’t see purple or other colors exactly as humans do, their mental picture of the world still involves some element of color rather than just black, white and shades of gray.
Do Dogs Have Color Preferences?
Although dogs see less color shades, they can still perceive some colors better than others. This means dogs may have color preferences even if they see a limited palette.
Studies show dogs tend to favor the following colors:
- Blue: One of the primary colors dogs see well. May be soothing due to association with water.
- Yellow: Also easy for dogs to see. Bright and high contrast against other colors.
- Green: Dogs can distinguish green better than red/orange. May stand out against brown environments.
So while dogs can’t appreciate the pop of vivid purple, they can discern paler shades against other colors. And they gravitate toward blues and yellows that stand out in their vision.
Conclusion
To summarize, the reason dogs can’t see vibrant purple is due to their dichromatic vision. They only have cones sensing blue and yellow/green light. Without the red cones, they miss out on the reddish wavelengths that make purple look saturated.
This means dogs likely perceive lighter purples as diluted grayish-blue tones. And darker purples probably appear black or very dark gray. Essentially, dogs can detect the blue in purple, but the red half of the color spectrum is invisible to them.
So while dogs don’t see the richness of the color purple, they may still distinguish it as a separate shade. Their vision focuses more on perceiving motion and contrast rather than all the vibrant colors humans enjoy.
