THE COLOR GRAY appeals to me, or perhaps I should say the full spectrum of grays, from pearly pigeon-breast gray to ashy or granite gray to weathered cedar-plank gray. And I like it spelled that way: g – r – a – y. Just as well, in both cases, since I live in a place called Gray’s River, which was named after Captain Robert Gray but could easily take its name from the panoply of leaden pewter-old aluminum skies that ceil this rainy place. I delight in a cloudy, foggy, or mist-ridden morning. In fact, I take keener relief from a cool gray break in a too-long stretch of overheated, UV-saturated, blue-sky days than the reverse.
Even so, I consider the human trait of color vision to be one of the greatest gifts of kindly evolution. As a kid, I loved the fact that our license plates bore the motto COLORFUL COLORADO and that, according to our fourth grade teacher, Mrs. Frandsen, the name Colorado referred to our state’s red rocks. I was crazy for Crayola, and the bright construction paper from which we fashioned turkey tails and autumn leaves for our classroom windows. Given this childhood infatuation with the rainbow, it isn’t surprising that seashells and butterflies captured my fancy, or that I asked for parrot tulip bulbs for my eighth birthday.
In “Kodachrome,” Paul Simon sings, “Everything looks worse in black and white.” While I don’t entirely agree — penguins, polar bears, early Hitchcock films, and a December day in Gray’s River would all suffer from colorization — I happily echo his sentiments when he sings, “Give us those nice, bright colors.” Or, as Cézanne put it, “Long live those who have the love of color — true representatives of light and air!” I find no conflict between this view and my penchant for hoary hues. After all, the very author of the gray I celebrate most days, the rain, sponsors as well the richest gathering of greens you could find anywhere. And my PhotoGray glasses not only lessen the glare of the sun, they also saturate tint. Yet we couldn’t even consider such questions were we not imbued with vision across the portion of the electromagnetic spectrum — lying between the ultraviolet and the infrared — that we call “color.”
Some people, when they discover that color vision is not general in mammals, feel bad for their pooches and pussycats. Yet our pets know nothing beyond their limited chromaticism, and even if they did, I’m not sure they would swap the exquisite sensitivity of their smell and hearing for what they might regard as the cheap trick of a parti-colored existence. Of the subtle range of perception they achieve through their noses and ears, we know nothing more than they know of our near-deaf progress through a colorful world. We haven’t even a word for nose-blindness! Yet anyone who reads Henry Williamson’s classic Tarka the Otter or Daniel Mannix’s The Fox and the Hound will apprehend something of our mammoth ignorance of these alternative sensory systems.
And what about the colorblind of our own species? Should we feel sorry for them? Two of the best butterfly observers I know, biologists Janet Chu and Paul Ehrlich, have orange-green colorblindness. In fact, Ehrlich’s research subjects of choice have been checkerspot butterflies — orange animals of green habitats. Perhaps their color-sight “aberration” (from our viewpoint) gives such people keener pattern recognition than the fully color-sighted ordinarily enjoy. Certainly such traits can vary. My wife, Thea, and illustrated-journal artist Hannah Hinchman both possess incredibly perceptive eyesight. Thea routinely spots four-leaf clovers in full stride, and hiking with Hannah in Idaho, I was astonished at what her peepers picked out. Yet both women’s acuity flags at the onset of dusk; each, in fact, has markedly poor night vision.
Our visual abilities, including the perception of color that we so often take for granted, arise through specific populations and configurations of rods and cones in the retina of the eye. Certain invertebrates, such as bees and butterflies, also see in the color spectrum, via clusters of ommatidia — parallel fiber optics that convey images as light waves through the thousands of lenses in their compound eyes to their optic nerves, and on to their brains. But these creatures tend to see in the ultraviolet as well, which we cannot. Observers often assume that a yellow crab spider secreted against a yellow daffodil achieves invisibility from its prey, but we cannot know how a UV-sighted insect sees the spider. Its camouflage has actually arisen to confer safety from its own color-sighted, avian predators. Conversely, the pink-and-purple dots and lines in the mouths of flowers, called nectar guides, fluoresce in ultraviolet, looking like neon strips to their insect pollinators. As a sharp student in one of my butterfly classes remarked, “Oh, I get it. Landing lights!” I often hear people declare that butterflies prefer this color of nectar flowers over that, but I mistrust such opinions because what looks yellow or mauve to us might look otherwise to an insect. UV perception often trumps color in mate recognition, too, in butterflies.
Among the vertebrates, we humans share color vision chiefly with birds, which also enjoy a degree of UV perception, according to current research. Color vision in humans and other old-world primates came about for adaptive reasons, often thought to include our omnivory. In his fascinating book on the evolution of human eating habits, Why Some Like It Hot, chile-pepper aficionado Gary Nabhan explains how peppers have coevolved with herbivores. Birds, insensitive to the fiery compounds with which hot peppers are graced and craving the carotene they contain, seek out peppers and pass the seeds through their guts intact. Mammals, whose digestive systems would harm the seeds, typically find capsaicin unpalatable and learn to avoid peppers. Humans are the exception, likely because of the power of peppers and other spices to preserve food and deter parasites. Those benefits may have outweighed the peppers’ oral burn, which many people have even come to enjoy. Presumably, birds pick out pecks of peppers by recognizing their bright red colors. It is interesting that some of the only other vertebrates that can discern chile peppers by color have come to value them as condiments.
Certain aspects of our relationship to the territory of tint strike me as even more curious. For example, why the peculiar adaptation of a sense of beauty, as it relates to color? Why should we thrill to a rainbow? Swoon before a coral sea? Experience, upon viewing a scarlet tanager for the first time, what the ornithologist Arthur Cruikshank Sr. once described to me as an “ornigasm?” I cannot say. I only know that when I see the russet fletching of a sharp-shinned hawk’s breast against the cones of a Sitka spruce, or a red-tail’s tail flashing past last year’s fronds of a winter cedar, something about the scene seems eminently right.
Nothing clashes in nature, but certain colors just look good side by side. For example, the cherry crown of a redpoll among rosehips deep in winter’s bleakness on a white Wyoming plain. Spring azures nectaring on bluebells, and swallowtails on lilacs at Easter time, as Paas-bright eggs hide in the fresh green grass below. The magenta of Parry’s primrose and Lambert’s locoweed in midsummer meadows. Then in September, Wilson’s warblers staging like lemon drops among scarlet currants before migration, and cinnamon monarchs floating over fallen peaches. I still love a winter’s monochrome on the lower Columbia, and admire the array of grays that gives rise to every rainbow. But I am no less thrilled to awake each day to a world produced in Technicolor.