They say dogs see the world only in black, white, and shades of grey. Cats, on the other hand, supposedly see a variety of colors, but at a more subtle level than we. Many birds, fish, and reptiles also see certain colors, albeit poorly. And some mammals even see yellow and blue the way humans do.

Why is color perception different between animals and us humans?  Basically, our retinas contain more types of cones, the photoreceptor cells in the retina that are responsible for converting light into color. The difference in the signals received from the types of cones allows the human brain to perceive a myriad colors.

But who’s to say that you truly see colors the way I do?

Think about it. We’re all different. We taste things differently, and we smell things differently. In both cases, something that is pleasant to one person may be repulsive to another. We look different. We speak differently. Some people use the right side of their brain, others their left. Most people shouldn’t wear Spandex, while others can pull it off. Even when comparing to animals’ capabilities, isn’t “the way us humans see color” just too general? Isn’t it possible that when I’m seeing red, you perceive it differently?

After all, how do I communicate to you what red is to me? It’s… well… it’s… it’s just red!

© iStockPhoto.com / Evgeny Kan

I know which things are red because someone taught me that the apple I was eating was red, or that the fire engine that screamed by our house was red, or that sexy two-piece swimsuit is red.

Sure, we can measure red in terms of frequency, wavelength, and vibration — but it’s still not possible to convey to you how I’m personally seeing it. If we were able to transplant my eyes and the part of my brain that is stimulated by color and processes images, and then connect them to the part of your brain that contains the background knowledge, images, and ideas, who’s to say that that we’d still “see” color exactly they way we did before?

When we determine whether or not animals can see color, we’re testing their ability to distinguish between differing colors, measuring responses to various wavelengths of light. That’s not the same thing as determining whether or not our perception of red is the same as their perception. For all we know, they don’t actually see in black and white, maybe they just see colors differently. Or, for that matter, they may see colors beyond our perception.

Which leads me back to my point that since we can’t really tell what colors look like to animals (not just what colors they can or cannot see) and we can’t even communicate what colors look like amongst ourselves, I’m willing to bet that when I see red, you’re seeing something quite different.

I’m just thankful for that two-piece swimsuit.