And, Why It Is Not Just Philosophical Navel-Gazing To Say So

This is a response to an article I most recently saw in PLSN, but in fairness to my friend and author of that article, Chris Lose, this is an argument I’ve heard put forward by many people over the years. The argument goes like this: color is a perceptual phenomenon, and therefore, “does not exist”. It exists, the argument goes, only in our minds, and this somehow makes it less real.

I find this line of reasoning to be highly suspect. It places all perceptual phenomenon on “non-existent” footing, including a lot of things that I think we would all agree exist, like smells, flavors, all of music, language, emotions…I could go on.

Briefly – because I think it will be helpful – let’s describe how color “works”. Light strikes an object, and some is absorbed, some is reflected, some might be refracted, and some will experience some strange quantum effects that won’t have any practical macro-world effects. (But which will be nonetheless cool) The reflected light will interact at an atomic or molecular level with whatever stuff the object is made of, and some of the reflected wavelengths, through that process, will be attenuated.

OR

Light is directly emitted by something – the LED subpixels that probably make up what you’re reading this on right now.

Either way, those wavelengths eventually enter your eyeballs, excite some rod and / or cone cells, send some electrical signals to your brain, then some hellawhack shiznit happens inside your brizzle and you see color.

The argument usually says that, because the color isn’t a physical thing that’s “out there” in the world somewhere, unable to be held in the hand or quantified in any way, that it does not exist. This argument hinges on a curious definition of “existence”, where something must have physical form, or at the very least, be able to be scientifically quantified. Color, the argument continues, doesn’t exist, but light, of course, does, and can be measured and quantified, and the various wavelengths that light comes in “trick” our minds into experiencing color.

The problem that I see with this argument is that ignores almost every subjective experience that human beings can experience. Music isn’t “out there” to be held in the palm of your hand, just vibrations in the atmospheric medium beating against your eardrums, causing similar electrical signals that cause the sensation of seeing. In the case of “music”, we use the term to describe several things: physical pieces of paper with symbolic writing to reproduce the music, but also the sounds of music themselves. Fundamentally, there is no difference between the experience of listening and the experience of seeing – both involve our brain’s interpretation of various frequencies of…whatever. Light, or oscillations in the air. And yet, most people would agree that music “exists”, despite our inability to hold it in our hands or quantify it in a meaningful scientific way. (Also see: any example of “contemporary classical” music.)

Further, I think it’s arguable that we can quantify color, as a physical process and (perhaps somewhat less accurately) as a perceptual process.* We can examine the wavelengths of light, and decide what color they are. Just because we have not sat down and mapped things down to the nanometer in terms of where red ends and orange begins does not mean that we couldn’t, just that there are better things to do with our time and we have only broad, but not specific, agreement on color terms. The science of spectrophotometry and colorimetry are based on quantifying reflected wavelengths and mapping human perceptions of wavelengths, most notable the CIE 1931 “half a colorful jellybean” chart you’ve probably seen a dozen times. We already break up the electromagnetic spectrum into waves of various sorts by defining where they begin and end – X-rays, gamma rays, etc. It’s a logical possibility that we could also quantify color names in this way.

As another example, take smell. Do smells exist? Taking the narrow definition of “existence” that we’re examining here, we would have to conclude “no”. Smells (and taste, for that matter) are perceptual phenomena that happen in our brain. A pepper does not smell or taste spicy. Pears do not taste sweet and pear-like. The pepper’s spicy-ness and the pear’s sweetness and pear-ness happen due to chemical compounds sending particular signals to our brain. Emotional states, and even body states, are another example. Does pain exist? Does happiness? Does ennui? Ask someone experiencing these states, they will certainly say they exist. And you likely would too, if you were experiencing them. And, on my account of existence, you or the people experiencing them would be absolutely correct in saying that they do.

Where the argument against color existing fails is an overly-narrow definition of “existence”, and perhaps a tendency toward an odd form of solipsism. (I don’t know that your red is the same as my red, and so forth.) We commonly agree that all sorts of perceptual phenomenon exist (the smell of a rose, the taste of a pear, the music of Beethoven) and there is no reason to exclude color from the common understanding of the word. Some of this argument relies on semantics – and most arguments of this sort rely on extremely precise definitions when we really examine their contours – but I think you’d be hard-pressed to find someone who draws such hard distinctions between things that exist physically and purely perceptual phenomenon**.

Color – like everything else we perceive – is generated by our minds, but – and this is important – typically corresponds to real physical things that happen in the world. So, we use the term color to describe the qualia of seeing and “decoding” particular wavelengths of light, just as we describe 440 hertz as the musical note “A”. To head off a related argument that I see sometimes argued in dubious YouTube channels, the same applies to the color magenta. Magenta exists just as much as any other color.

Here I want to move onto the second part of my counter-argument, and go a little bit further than saying that perceptual phenomenon exist in and of themselves. Color can also refer to the physical processes that produce the wavelengths in question, and in this sense, color also exists as a physical process.

For instance, if you were to look at a Monarch butterfly, you could say to me “The butterfly’s wings are orange.”, and this would be true. They have (or perhaps “generate” or “cause” are better words?) the color orange – there is a real, physical, tangible thing that’s happening at an atomic level that is causing some of the white light to be absorbed, and orange light (light in particular wavelengths that we call orange) to be reflected, and then a complicated thing happens in our brain and our eyes and we experience orange. The color is the process at the physical level, and it is also the experience that we have, and they cannot be cleanly separated from each other. I therefore submit that color exists in two senses of the word – both physically (it would exist whether we see it or not) and as a perceptual phenomenon that happens in our eyes and nerves and various cortices that contribute to the qualia.

Why does this argument matter?

Well, we have words, and those words have meanings that we should be careful and precise with. We have a word that, on my account, refers to the whole of the physical process plus the experiential phenomenon, and I think my account accurately describes the common understanding of what we mean when we say “color”. Saying “color does not exist” is something I think gets said for the shock value, because it’s so intuitively (and, I would argue, in reality) untrue. But – like the equally incorrect “magenta is a fake color” meme of the last few years – it doesn’t advance people’s understanding, it just gives people an incorrect understanding about an interesting perceptual phenomenon. I suppose in all charity it might spur someone to go looking into color theory and vision processes, but it’s just as likely to cause confusion repeated at a cocktail party by someone who doesn’t know what they’re talking about. It is the lighting designer equivalent of those “gotcha” jokes that hinge on the ambiguity of language to get a laugh.

Guys, color exists. This month, put up your pride / trans / whatever you fly flag, wear your most outrageously mageneta socks, and bite into the greenest of pears, and gaze at the most orange-est and red-est and yellow-est of sunsets you can lay your eyes on. And don’t let anybody tell you that the colors of all these things is anything less than totally real.

*There are interesting developments in mind / machine interfacing that might in the future make it possible to know if your red and my red and the same, and that’s very interesting.

**Of course, there are philosophical arguments regarding qualia, which is the philosophical term of art for mental states, and also philosophical arguments about existence and maybe we’re all just brains in vats or potatoes floating in space, but these arguments are beyond the scope of this already somewhat philosophy-flirtatious article.