On Color

by David Kastan

Take, for example, “the dress” (Figure 8). On February 26, 2015, the dress became an Internet sensation. A post on Facebook asking about the colors of the dress was reposted on Tumblr, and somehow this went viral. Tens of millions of people, from Katy Perry and Taylor Swift to John Boehner, debated the colors of the dress on Twitter. “From this day on, the world will be divided into two people. Blue & black, or white & gold,” tweeted Ellen DeGeneres.14 For a week or two, people passionately argued which it “really” was, until eventually the meme was swallowed up in the news cycle.

  “The dress” could be thought to pose a problem for Russell. What are the colors that we know “perfectly and completely” when we looked at the dress? Russell would presumably have said that they are the colors that each individual sees when looking at it. That is, the colors are gold and white—or they are blue and black. That there is a disagreement seems to be a function of the ways individual brains “correct” for the presumed lighting condition. They differently decide what visual information to process or discard as people looked at what in any case wasn’t a dress at all but a photograph of one, and a photo that almost everyone was viewing on a computer screen. But whichever colors you saw would be, in Russell’s account, the colors you knew. That was good enough. Whichever colored dress you saw, you knew its colors “perfectly and completely,” even if what you were seeing was only a trick of the light played upon the brain or a con job pulled off by the mind.15

  Ultimately all color might be said in some fundamental sense to be a trick of the light or a con job. But for Russell, that isn’t important. From revelation theory, “what you see is what you get”—that is, “knowledge of the color itself,” as Russell says, rather than knowledge “of truths about it.” “I know the color perfectly and completely when I see it, and no further knowledge of it itself is even theoretically possible.”

  But it is difficult to avoid thinking that the adverbs “perfectly and completely” here are more than a little perverse, regardless of how precise the words might be in their philosophical intention. At the very least they seriously underperform, and maybe so does the theory. For most of us, revelation theory probably doesn’t seem worth the effort to understand it. It is no more satisfying than any of the other philosophical theories of color, and maybe it’s less. One might reasonably wonder if the revelation provides any knowledge at all.

  Still, unlike many of these theories, it usefully reminds us of the irreducibility of our experience of color. And it also reminds us that, in all non-specialist contexts, the word “color” unproblematically refers to a conspicuous aspect of the way things in the world look to us. That, too, is good. The problem, however, is that color is so very problematic. There is so much more to say.

  We can see that roses are red, but we have to see that. The necessity here comes not from the fact that it is the color of the roses that is there to be seen but because no explanation could ever make that “red” imaginable to a person who was congenitally blind. And the roses wouldn’t even be red if we weren’t there to see them. But at least they are red when we do.

  SEEING RED ?

  Well, a lot of roses are—at least in daylight, or with the lights on. Just ask a florist, though a florist who isn’t color-blind. Perhaps as many as 8 percent of men have some color discrimination deficiency, but apparently fewer than 1 percent of women. No one, however, is truly color-blind. It is a misnomer for a set of visual deficiencies caused by anomalies in the functioning of the cones, which serve as one of the two types of photoreceptor cells in the retina. In the rarest and most extreme form of color-blindness, called achromatopsia, sufferers have no functioning cones at all and process light exclusively through rods, the receptor cells of the retina that support our vision at low levels of light. With only rods detecting light, the world appears in shades of gray.

  In the more common forms of the deficiency, one of the three types of retinal cones doesn’t function, affecting the ability to detect colors in specific sectors of the visible spectrum. In normal color vision, the three types of cones, each responsive to a different subset of the spectrum, overlap, enabling its entirety to be detected. For most color-blind people, it is difficult to make some color distinctions, most often between red and green but sometimes between yellow and blue. The Ishihara test, named for the Japanese professor Shinobo Ishihara, who first developed the technique in 1917, uses a portfolio of discs with variously arranged colored dots for the assessment of color vision.

  In Figure 9, “normally” sighted people see the numeral 6 formed of orange dots. People who are color-blind, however, usually see no number at all in the disc, only, as a “color-blind” friend reported, “a bunch of colored circles: yellow, blue (maybe?), green, and some orange.” Even in our age of euphemism, sensitively designed to prevent invidious comparison, we can probably with good conscience call this a deficiency rather than just a difference. But what should we say about the colors that are seen by color-blind people? Are they mistakes? Misperceptions? Illusions? “Yellow” might be the right name for the color that a color-blind person sees. It is just not always the right name for the color that most of the rest of us are seeing then. We (that is, normally sighted people) can probably legitimately say that their “yellow” is a mistake, because color names get attached to colors as they appear to normally sighted people in normal lighting conditions, though our colors are illusions, too.

  One could raise various objections to the appeal to normalcy (for example, its definition is usually a function of circularity—some version of: “normal is what normally is thought to be normal”—or of some statistical prescription: such as what a majority of people experience). But the objections all seem to be outweighed in this case by the fact that “normal” color vision is defined neither circularly nor statistically but qualitatively. Normal color vision involves the optimal functioning of the three sets of cones in the human retina able to absorb the energy waves in the visual spectrum. Other forms of color vision are categorically deficient, with something limiting the spectral sensitivity of one or more of these sets of photoreceptors. So colors, properly named, are what optimally functioning visual systems see, not what a “color-blind” person is seeing.

  FIGURE 9: Ishihara Plate No. 11

  A pigeon, however, would laugh if it could. Pigeons have photoreceptors in their eyes that function much like those of the human eye, only they have an additional set of cones. Some scientists think they actually have two additional sets. Pigeons are, therefore, what is called tetrachromats (or pentachromats), while normally sighted humans are trichromats. What this means is that where our three kinds of cones have specialized sensitivities to light of different wavelengths allowing the visible spectrum to be perceived, a pigeon has four or maybe five, allowing a more complex color experience than we humans are capable of. Pigeons see colors we don’t, and they see the colors we do see differently than we see them. Our roses don’t look red to them.

  Is this important? Should we care? We readily admit that eagles have better distance vision than we do and that owls can see better in the dark. Yet something seems different about admitting that pigeons have better color vision than we do. It is no less true than the other claims for avian visual superiority, but something more seems to ride on it. Maybe color matters too much for this concession.

  We know that a pigeon’s color-processing mechanism is more refined than our own, so what should we say about the colors that are seen by normally sighted people? Are they mistakes? Misperceptions? Illusions? “Yellow” might be the right name for the color that a normally sighted person sees. It is just not always the right name for the color that most of the pigeons are seeing then.

  Normally sighted people seem to be in the exact relation to pigeons as color-blind people are to the normally sighted. So maybe pigeons should get to decide which is the mistake. Or should we say that standards of correctness exist only within individual species? What a normally sighted pigeon sees as red is red for pigeons, whereas
what a normally sighted human sees as red is red for humans. These aren’t the same color. But so what?

  Perhaps species-specific color names is a good solution. It avoids an unthinking anthropocentrism, and it preserves the functional definition of color as what is generated by the neural activity processing the wavelengths of energy that reach the eye. And it is also good because it doesn’t insist that either pigeon red or human red is the “real” color, whatever that might mean.

  What is less good about it is that it makes it harder to answer the question “What is it to be a color?” since it seems to suggest that whatever a color is, it is not a specific visual experience. The color we see will be seen as a different color by a pigeon, and maybe different still by other creatures. Red roses are, then, at least two different colors. Jonathan Cohen, an excellent philosopher, argues that this is indeed the case but isn’t troubled by the implications: “We can hold that one and the same object can be simultaneously green for your vision and not green for the visual system of the pigeon on your window ledge.” For Cohen, this inclusiveness poses no problem, since, as he says, “The properties perceived by pigeons and other non-human organisms are, even if they are not the very same properties we perceive, at least properties of the same kind—in a word, that they are colors.”16

  But “in a word,” maybe “colors” are exactly what they are not, if only because pigeons don’t have that word. Uniquely, human beings conceptualize color sensations and cognitively assemble these as the particular “colors” we see and as the category of experience we think of as “color.” Most creatures can detect and process light waves, distinguishing different reflectance properties. Clearly the ability to perceive and discriminate colors offers various kinds of advantages: for mating, finding food, or recognizing predators. But it isn’t apparent that any of these nonhuman creatures, however sophisticated their visual systems are, have any ability or any need to conceptualize color rather than merely to experience it. Pigeons (and other creatures) have color sensations; only humans have colors.17

  And, of course, only we have language to name them. “Color is not ‘our’ term,” says another philosopher writing about sense perception and defending exactly what we have just denied. “We must accord pigeon colors exactly the same authority as … the colors that humans experience.”18 “Principled” is his word for his gracious concession. But “color” is in fact only “our” term. Who else could it belong to? Pigeons don’t have terms. “Color” (in whatever language) is our word that we use to refer to a particularly sensuous aspect of the world we see, and thus we get to decide what color is mainly because we are the only creatures that can.

  Now this may not prove that pigeons and other animals lack a concept of color (as opposed to experiences of colors), only that they have no word for it, as well as no word for anything else. But there is no reason to think that they do have such a concept. There is no sign of it in their behavior, nor does it offer any obvious evolutionary advantage.

  But that line of reasoning demands that we ask what advantage humans get from their conceptualization. To the degree that we are primates, we share in all the creaturely rewards of detecting and classifying. We, too, recognize ripe fruit in part through color cues; sometimes we might even recognize willing mates. The advantages of conceptualizing color may not be so obvious, though that is the subject of the rest of this book. Here, it is probably enough to point out that the evolutionary advantages of our ability to conceptualize anything at all are everywhere around us. They are the reason, to put it bluntly, that we experiment on pigeons instead of it being the other way around.

  And they are the reason that florists are right to insist that most of their roses are red, although pigeons must often shake their heads, certain that they know better.

  CHAPTER TWO

  What is orange? Why, an orange,

  Just an orange!

  CHRISTINA ROSSETTI, “What Is Pink?”

  Orange

  IS THE NEW BROWN

  FIGURE 10: John Baldessari, Millennium Piece (with Orange), 1999

  The human eye can distinguish millions of shades of color, subtly discriminating small differences of energy along the visual spectrum. No language, however, has words for more than about a thousand of these, even with compounds and metaphors (for example, a color term like “watermelon red” or “midnight blue”). Most languages have far fewer, and almost no speakers of any language, other than interior designers or cosmeticians, know more than about a hundred of these.

  In whatever language, the available color words cluster around a small category of what linguistic anthropologists often call basic color terms.1 These words do not describe a color; they merely give it a name. They are focalizing words, and are usually defined as “the smallest subset of color words such that any color can be named by one of them.”2 In English, for example, “red” is the basic color term for a whole range of shades that we are willing to think of (or are able to see) as red, whereas the names we give any of the individual shades are specific to them and don’t serve a similarly unifying function. Scarlet is just scarlet.

  Most of the individual words for shades of red take their names from things that are that particular shade: maroon, for example, which comes from the French word for chestnut—or burgundy, ruby, fire engine, or rust. Crimson is a little different: it comes from the name of a Mediterranean insect whose dried bodies were used to create the vibrant red dye. Magenta is also different. It takes (or, rather, was given) its name from a town in northern Italy, near which Napoleon’s troops defeated an Austrian army in June 1859, during the Second Italian War of Independence.

  But whatever the source of these color names, all of these are just implicit adjectives, in each case modifying the withheld noun “red.” Sometimes, however, the link of the referent to its color seems a bit obscure. In 1895, a French artist, Félix Bracquemond, wondered exactly what shade of red “cuisse de nymphe émue” (thigh of the passionate nymph) might refer to.3 Unsurprisingly, that name didn’t last very long, but a successful cosmetics company today does sell a lipstick color it creepily calls Underage Red.

  All the other basic color terms in English are like red in that they similarly subdivide into descriptive color words mostly derived from things that are that particular shade. Green, for example, works this way. Chartreuse takes its name from a liqueur first made by Carthusian monks in the eighteenth century. And there is emerald, jade, lime, avocado, pistachio, mint, and olive. Hunter green takes its name, unsurprisingly, from a shade of green worn by hunters in eighteenth-century England. Hooker’s green takes its name from … No. It takes its name from William Hooker, a nineteenth-century botanical artist, who developed a pigment for painting certain dark green leaves. No one is quite sure about Kelly green, beyond an association with Ireland. Perhaps it is the imagined color of what leprechauns wear.

  Orange, however, seems to be the only basic color word for which no other word exists in English. There is only orange, and the name comes from the fruit. Tangerine doesn’t really count. Its name also comes from a fruit, a variety of the orange, but it wasn’t until 1899 that “tangerine” appears in print as the name of a color—and it isn’t clear why we require a new word for it. This seems no less true for persimmon and for pumpkin. There is just orange.

  But there was no orange, at least before oranges came to Europe. This is not to say that no one recognized the color, only that there was no specific name for it. In Geoffrey Chaucer’s “Nun’s Priest’s Tale,” the rooster Chaunticleer dreams of a threatening fox invading the barnyard, whose “color was betwixe yelow and reed.” The fox was orange, but in the 1390s Chaucer didn’t have a word for it. He had to mix it verbally. He wasn’t the first to do so. In Old English, the form of the language spoken between the fifth and twelfth centuries, well before Chaucer’s Middle English, there was a word geoluhread (yellow-red). Orange could be seen, but the compound was the only word there was for it in English for almost a thousand ye
ars.

  Maybe we didn’t need another one. Not very many things are orange, and the compound works pretty well. “Where yellow dives into the red the ripples are orange,” as Derek Jarman says.4

  By the mid-1590s, William Shakespeare did have a word for it—but only just. In A Midsummer Night’s Dream, Bottom’s catalog of stage beards includes “your orange tawny beard,” and later a verse in his song describes the blackbird with its “orange tawny bill.” Shakespeare knows the color orange; at least he knows its name. Chaucer doesn’t. Shakespeare’s sense of orange, however, is cautious. His orange exists only to brighten up tawny, a dark brown. Orange doesn’t make it as a color in its own right. It is always “orange tawny” for Shakespeare. He uses the word “orange” by itself only three times, and always he uses it to indicate the fruit.

  Through the late sixteenth century in England, “orange tawny” is commonly used to mark a particular shade of brown (even though chromatically brown is a low-intensity orange, though no one then would have known that). The word “tawny” often appears alone; it names a chestnut brown, sometimes described as “dusky.” “Orange tawny” lightens the color, inflecting the brown away from red toward yellow.

  The prevalence of the compound demonstrates that orange was recognizable as a color word. The compound wouldn’t work otherwise. Nevertheless, it is still surprising how very slowly “orange” on its own begins to appear in print. In 1576, an English translation of a third-century military history written in Greek describes the servants of Alexander the Great dressed in robes, some “of crimson, some of purple, some of murrey, and some of orange colour velvet.”5 The translator is confident that “murrey” will be identifiable—it is a reddish purple, the color of mulberries—but he needs to add the noun “colour” after “orange” for its meaning to be clear. It is not quite orange yet, but merely the color that an orange is. Still, two years later, Thomas Cooper’s Latin-English dictionary could define “melites” as “a precious stone of orange color.” In 1595, in one of Anthony Copley’s short dialogues, a physician tries to ease the anxiety of a dying woman by telling her that she will contentedly pass away “even as a leaf that can no longer bide on the tree.” But the image seems to confuse rather than comfort the woman. “What, like an orange leaf?” she asks, obviously referring to the color of the leaves in autumn rather than to the leaf of the fruit tree.6 But what is most significant about these examples is that they might be the only two sixteenth-century uses in English printed books of “orange” used to indicate the color. In 1594, Thomas Blundeville had described nutmeg losing its “scarlet” color and turning “unto the color of an orange.”7 But this, of course, is referring to the fruit. “Orange” was still struggling to be the word for orange.