The "Color" Grey

A few years ago, someone asked me my favorite animal as an "icebreaker" question.

I have a lot of favorite animals and many of them are incomparable.  I have a particular fondness for hamsters (as a very good pet) and for rhinos (as probably not a very good pet).  I like hoatzins, which are a bird,which I have given their own category outside of "animal" because if we include birds and fish and dinosaurs into "animal" then it gets even harder to choose a favorite animal.

But my knee-jerk response was to offer up the objectively correct answer to the question: dog.

Dogs are not simply my favorite animal.  They are everyone's favorite animal, and that is because they are designed to be.  They were the first domesticated animal and they've been selectively bred for 10,000 years to be our favorite animal.  The incredibly long, long history of man and dog, interwoven for over four hundred generations of humans, makes dogs the best animal, the impartial favorite of mankind, and their influence over our civilization and the ways we've co-evolved cannot be understated.

Anyways, after I said "dog," I was informed that this was a "boring" answer and that I seemed like a boring and uncreative person.

I think a lot about that interaction because if that person had engaged with my answer, we could have had a real chat about some deep, heavy topics.  In the end, they were the shallow one for assuming there was no nuance to the answer, because the answer was a "common" one.

But sometimes common answers are common for a reason, even if folks can't articulate those reasons well (or, in my case, aren't afforded the option).

And sometimes "boring" answers are less boring than they seem at face value.

So today I'd like to talk about one of my favorite colors: grey. According to the sixth sentence on grey's Wikipedia page, "in Europe and North America, surveys show that grey is the color most commonly associated with neutrality, conformity, boredom, uncertainty, old age, indifference, and modesty. Only one percent of respondents chose it as their favorite color." 

Way to do the color grey dirty, Wikipedia.

A seemingly "boring" color, it's actually one of the most interesting.

(I have a minor bias; my first pet was a grey cat and I have always been partial to grey cats.)

 

This isn't the first time I've talked about colors.  But grey is a unique one in that it's not really technically a color at all.  

Most people would agree that the definition of "grey" is some kind of halfway point between black and white.  But most of us know that white and black also aren't colors.  Black is the absence of color.  There's no place for it on the spectrum of visible light; rather, what we call "black" is what we see when all color is absorbed.  And, likewise, white isn't on the spectrum; it is the spectrum.  White is what we see when all colors are reflected back to us.

In mathematical terms, we could also say that black is zero and white is infinity.

So, mathematically... what the hell does that make grey?  It would seem it's a mathematical impossibility at first glance, a mixture of zero and infinity, of everything and nothing.  A real divide-by-zero kind of situation.

Before I explain to you what grey really is, I'd like to address the spelling of it.  The first recorded use of the word "grey" dates back to the year 700 A.D.  You might be aware that, in our modern language, there are two spellings.  "Grey" is commonly used in England (the "e" stands for "England") and "gray" is commonly used in America (the "a" stands for "Abraham Lincoln of the United States").  This division in spelling is purely aesthetic and there is no correct answer.  Both spellings derive from the Old English word grǽg.  As we transitioned into Middle and then Modern English, folks like Chaucer played fast and loose with grǽg, spelling it both "graye" and "greye."  Seeing that everyone does seem to agree it should have an "e" in there, I opt to spell it "grey."  But whatever spelling you enjoy, from grey to gray to gruy (the "U" stands for "United Kingdom") is fine.

 So, back to math. 

How can we define grey mathematically?  The answer is that "grey" isn't defined by a wavelength (as are most colors) but instead of its absorption and reflection (just like black and white).  Grey exists outside of the spectrum of visible light.  When you see grey, what you're seeing is all colors being absorbed and reflected at the exact same percentage.  "White" is all colors reflected at 100%.  "Black" is all colors being absorbed at 100%.  And grey is every percentage in between, when all colors are getting equal reflective treatment.  In this sense, "white" and "black" can be seen as shades of grey themselves, albeit with far less problematic messaging than the E.L. James novel.  

(Incidentally, while "shade" is often used to refer to a darker or lighter color, let it be pointed out here that "shade" actually refers only to darker saturations, and the technical term for a color that is lighter than the base color is a "tint," making the term "tinted windows" highly confusing to anyone who is really pedantic about color theory.  The correct term for shade would be "tone."  A tone refers to mixing a color with grey, which alters its tone by making it either darker or lighter.)

I'm happy to report that grey is such a unique "color" that it has its own special little category. Since it's not a "true" color (in the sense of being on the visible spectrum of light), grey is categorized as an "achromatic color," that is, a color we can see but one that lacks hue.  ("Hue" refers to the relative mixture of colors within a color.  For example, a light green might have a "yellow hue.")

Achromatic colors (also sometimes called "neutrals," although this category includes "chromatic neutrals," which are greys with bits of color mixed in) are defined by colors that contain all wavelengths of light within them but have no saturation or dominant hue.

I was deeply curious as to when this color category was formed.  We know that Isaac Newton famously observed the separation of white light into the visible spectrum of color in 1666, using a prism, and that Thomas Young was the first to measure and define the wavelengths of color in 1802.  But "grey" is, obviously, visible, and as early as 1374 we were making distinctions between tones of grey ("æsce grǽg," or ash grey).

The answer isn't an easy one and I unfortunately couldn't tell you.  It might be a concept that predates our understanding of color in the first place.  Back in 350, Aristotle suggested that there were five "pure" colors (red, green, blue, purple, and yellow) and that all other colors arise from mixtures of them along with black and white... "colors" that he clearly thought of as "non-colors," with their own little outsider category.  And not much has changed since then.  In 1925, F.L. Dimmick published a paper in Psychological Review titled "Discussion: The Series of Blacks, Grays, and Whites" arguing for achromatic color class, and later, in 1949, E.G. Boring published a paper in L'année psychologique titled "A color solid in four dimensions" making the same argument.  But the "official" creation of the "achromatic color class" didn't properly arise until the advent of the digital screen, when, to display color, all colors needed to be defined in terms of RGB, much like the human eye "defines" or perceives them with its three types of cone cells.  Achromatic greys, on a computer screen, are input as "colors" in which the RGB values are exactly equal.  (Standard "grey" has the hex code #808080, which is 50.2% red, 50.2% green and 50.2% blue.  Or in other words, halfway between black and white, with no hue or saturation.)

So, there you have it.  Grey is not nearly as boring as you might have once thought.  And it's not only interesting and seeped in history and math, but it's also probably the color you see most often, out of all the colors.  Because every time you close your eyes, or try to see in the dark, or perceive "grey" because there's not enough light to make out colors, what you're seeing is a specific color called eigengrau, or "intrinsic grey."  Also horrifyingly called "brain grey," this cozy "default" color exists due to a visual adaption to human vision, one that helps us see in the absence of light by emphasizing light/dark contrast instead of color tones.

In other words, like dogs, it's something that's been with us for thousands of years, unappreciated due to its apparent "commonness," but with a long and fascinating history, so long as we're willing to look for it.