A TUMULTUOUS BRUISE FLOATS OVER THE horizon, creating a color that hovers between red and blue, not really either, or neither, but an ambiguity of sensation that makes the eyes tremble with uncertainty. We call this event purple. When it’s bright enough to see things clearly, nature becomes green again. Earth life equals green everywhere I look, from the ghostly greens of new shoots and beans to the cavernous green of aged leaves. We just happen to live on a world where plants broadcast green. Using sunlight, they mint organic compounds through the pigment chlorophyll, which absorbs red and blue light, not green. We see all the greens scattered, filling the air with a huge exhalation of color, and identify nature by its signature of loss: green. So, ironically, the colors we relish happen in the mind, not in the world. Apples are everything but red—when light hits them, only the red rays are reflected into our eyes, and we think: That’s red!
On other planets, organisms would adapt to the brew of light emitted by their own type of star, filtered by their own tailor-made atmosphere. Hotter stars, for instance, give off more blue light. It might be fun living in a blue-hued nature, unless the sky were blue, too, which could leave one in a muddle, unless one evolved to gauge the subtle differences. Photosynthesis is so successful on Earth it’s likely to power life elsewhere. Red dwarfs (the most common stars) emit less visible light than our sun and vegetation on their planets might photosynthesize in black to make the most of low light by absorbing all colors. We, too, have adapted to our sun’s dialect of light. Florida is a land where the leaves are those in paintings by Goya: dark lugubrious greens. Pale greens would fry in the sun, so the glossy leaves of the hibiscus, palm, and fig use a reddish-green pigment as sunscreen (it wicks away extra sunlight).
In Northern winters, the branch tips of blue spruce look glazed with ice when they’re flushed with new growth, a blue so startling the tree goes by its name. Thinking of colors we identify with nature—avocado, sea foam, mint, turquoise—I wonder how we missed blue fir, a shade of talcy blue that hovers close to light green. Many languages don’t distinguish between blue and green at all. The Japanese regard our green traffic signals as blue, for instance, while to the Vietnamese both sky and leaves are a green-blue they can refine as sky green-blue or leaf green-blue. As late as the turn of the twentieth century, the Swedes were using the same word for blue and black, and although at first that seems horribly limiting, and maybe even morose (unless you think of black as a shade of blue), it would have spurred wonderful imagery as people sought ways to specify exactly the shade of blue they meant. Was it jay blue, sapphire blue, wild-lupine blue, window-cleaner blue, denim blue, neon blue, open-water blue, chicory blue, ultramarine, indigo, periwinkle, or the blue shadow at the bottom of a hole you dig in the snow? In contrast, Russians and Italians see light blue as a separate color from dark blue, just as we call light red pink. Welsh poets say yng nglas y dydd, “in the blue of the day,” when referring to dawn, and also use glas (blue) as a symbol for birth and death. In their lyrical trust not only does day and life dawn, so does death when one dawns on the other side.
On our planet, green, blue, and red seem to dominate—the blue skies and ocean, of course, the greens of leaves, and reds so sense-stirring we’re bowled over by them. The redder the sunrise or sunset the more it thrills us. The color of blood and fire, red excites the eye. When a man sees bright red (battle uniform, say, or a red-hot mama in a slinky red dress), his adrenal gland secretes more adrenaline to tune his body for trouble. In lab studies, red triggers the release of the hormone epinephrine, and blood pressure increases, the pulse speeds up, breathing quickens, and perspiration follows. The body instinctively treats red as an aggressive color, a cue for arousal and energy. No one can stay calm long in an endlessly eye-catching red room. Coca-Cola, Campbell’s soup, Colgate toothpaste, and countless other companies flash red in their packaging to entice customers. It’s small wonder the word red sashays through our language. Anger us and we see red. An unfaithful woman is branded with a scarlet letter. In red-light districts people buy carnal pleasures. We like to celebrate red-letter days and roll out the red carpet, while trying to avoid red tape, red herrings, and being in the red. We carry the color red in our veins, we are soft sacs of a red liquid. Spill a little of it and women produce life. Spill a lot and we die. And that’s just us; other creatures perceive red in differently fascinating ways.
At the moment, I’m savoring a fluorescent red sunrise whose sienna fleece contrasts strikingly with pale pink banners. A scarlet male cardinal has landed on a palm leaf. His dusky mate, perching in a nearby hedge, is not so eye-catching. To us, that is. Other cardinals find her perfectly red, especially when she flirts by puffing up and shivering like a baby bird. Were there baboons in the street, the females would be flashing red netherparts. Not all mammals see red as I do. Cats live in a black, white, and gray world, one I can glimpse. Since only the cone cells of our eyes sense color, and they’re concentrated in the center, everything I see out of the corner of my eye is colorless. That part of my retina views the world in cat-like monochrome. A folder propped up beside me is a gray blur until I turn my head and center it: green cardboard filled with white notebook pages written on in black, flagged with bright yellow Post-its, on one of which the word leeches has been scrawled in green ink. Color-blind people, like Operation Migration’s whooping crane guide Bill Lishman, have trouble telling red from green—a lucky break for the cranes since, as a boy, Lishman had planned on piloting planes in the Royal Canadian Cadets, who turned him down because, by global agreement, red and green runway lights guide pilots, and planes flash a red light on the left wing, green on the right.
Male and female barn swallows, cedar waxwings, and most of the world’s songbirds appear the same color to me, but they see beyond me into the realm where plumage reflects ultraviolet light and flowers are decorated with to-us-invisible targets and landing pads—for birds see more colors than we do and read much finer distinctions among them.
In nature, flashy dress usually signifies sex or danger. Arrow-poison frogs warn in screaming colors: Don’t touch! Monarch butterflies, heart-stoppingly beautiful with their digitalis-like poison, signal: Don’t eat! Banded bumblebees warn of stingers, diamond-backed rattlers of venom, with colors that proclaim: Dangerous if attacked or eaten! Even plants read and respond to color. When tomato plants are exposed to far-red, well beyond human vision, they react as if they were racing rivals and spiral high, boost the chlorophyll and protein in their leaves, and fruit earlier than their neighbors.
In the days before synthetic colors, some red dye came from such plant sources as henna, madder, or archil, and others from insects like Laccifer lacca, excellent for lacquering or shellacking wood. But competitive dyers also sought a perfect red, by which they meant commercially perfect: stable, easily absorbed by fabric, and resistant to fading.
When Cortés galloped into Mexico as a four-legged god, he discovered that the emperor, Montezuma, claimed the right to wear a resplendent solar red, and imposed on his subjects a special tax to be paid in cochineal insects, from which the vibrant dye came. The Spanish quickly monopolized the world’s supply of cochineal, which became both high-status and expensive. In 1587 alone, the Spanish shipped sixty-five tons of it home. Other countries coveted it, pirated shipments from Spanish galleons, and tried to raise it cheaply in their own colonies. The equivalent of corporate espionage ensued.
Much as they loved the luxe red, people tried like the dickens to unpuzzle the dye, without success. For the longest time they couldn’t even agree if it was plant or animal. In an era of poor microscopes, cochineal’s secrets simply defied scrutiny, and as a result it spawned recklessly high bets and lots of controversy. As it turns out, cochineal is a fragile little beetle, related to scale, that lives on the prickly pear cactus. The female produces carminic acid for defense against ants and the like, and she’s pure red. Pinch her and she bleeds a red so fierce it gives cloth a dye that can outlast empires. Male and female differ wildly in this species, and that added to the confusion, with rumors of angelic inseminators. The flightless females crawl around prickly pear cactus, waiting for their “flying husbands” to descend. After that, alas, they’re engorged with a pure red precious to European hominids, at times more craven than a cadre of ants.
Why not set up cochineal colonies in Europe? Cochineal is notoriously hard to ranch. For centuries, Mexicans enjoyed success by hand-rearing small numbers, which they were able to breed for size and color, until they arrived at a robust new species twice as large as wild cochineal. Even so, cochineal insects were sensitive to weather, and it took seventy thousand dried insects to produce one pound of red dye. In the days before synthetic dyes, the more European monarchs and gentry wore the fashionable scarlet red, the more cochineal figured in society and fed or bled the economy.
Most often we see red as decorative, not purposeful, not exploitable. But color is mainly trickery, much of it designed by clever plants to waylay a potential pollinator, or used by animals to scare away a predator or share important (often life-and-death) information. Like other life-forms, we unknowingly employ red to signal our intentions or moods. An emotional octopus changes color, glowering red when angry; we blush red when embarrassed. Like the hummingbird and the tomato plant, we’re passionate about red, a blood color that excites our senses, sometimes into fright, but most often into arousal. Like other animals, we tell time in part by the color of the sky, and follow color as a feeding guide, to detect ripe fruit, edible plants, and fresh game. We even use color for spiritual nourishment.
At dawn in India on the spring equinox, as a priest with red-stained skin chants, an excited crowd tosses clouds of red powder into the air, symbolizing pollen, showering everyone in crimson. Elsewhere at dawn, church cardinals are donning red robes, women applying red lipstick, workmen planting red stop signs, lawyers and politicians knotting red “power ties” around their necks before they enter the scorching fray.