WE HAVE, OF COURSE, quite a number of color theories, and of techniques that apply them. Surprisingly, however, we seem to have no satisfactory theory on the cultural role of colors. No doubt the symbolic standing of various colors in different cultures has been the subject of ethnological, anthropological, and psychological studies, and the results have surely been applied by people in such fields as publicity, marketing, architecture, and design. But we seem to have no meaningful theoretical answers to questions like, Is there, or is there not, an underlying pattern to the periodic changes in coloring of our cultural landscape? Why does the classical Greek town seem to have been so colorful, and the Hellenistic one so monochromatic? What is the explanation for the grayness we associate with 19th-century cities (coal? money? printed matter?), and can Impressionism be understood as a revolt against it? Why are capitalistic societies so much more colorful than “people’s democracies,” even in “colorful” places like China and Cuba?
Any cultural theory of the colors would have to consider them as the elements of information-bearing codes. In traffic, for instance, red means “stop” and green means “go,” in a code that is valid worldwide. Now codes—the assignment of ordered meanings to particular phenomena—have so far been used essentially to carry information from person to person. We have agreed on certain drawings, for instance, to constitute the code of writing. Today, however, codes are needed to carry information from people to machines—computers, or robots. The digital code is an example.
Machine codes must be clear and distinct, because machines aren’t made to decipher hidden or ambiguous meanings, as humans do when they read poetry or look at painting. And the issue of the clarity of the codes that mediate between humans and machines beats back upon the codes that mediate between humans. Is it possible, or desirable, to establish interpersonal codes—color codes, for example—that would be both as articulate as the codes we have devised to talk to machines, and also as unambiguous? Could a color code become a sort of universal Esperanto, complementing or even substituting for spoken and written language?
Generally, codes are built in one of two ways: they are “denotative” or “connotative.” In a “denotative” code each symbol “means” a single element among the meanings that the code exists to convey, and each element of that universe of meaning is represented by a single symbol. Such a code is said to be “bi-univocally” related to its universe of meaning. In a “connotative” code, each symbol may “mean” several elements of the universe of meaning, and each element of that universe may be represented by several symbols. Such a code is said to be “equivocally” related to its universe of meaning. Except in a few relatively recent instances, such as the traffic light, or color-coded price tags, colors have so far mainly been used equivocally—for example in painting.
Denotative codes have the merit of clear meanings, and are often used in scientific communication. The system of numbers is a denotative code. But they have the disadvantage that their ability to convey meaning is “poor”: they are somewhat inflexible, being unable to evoke the content of whatever intervals fall between their symbols (for instance between “1” and “2”). Through these intervals, large parts of the universe of meaning escape. In connotative codes, on the other hand, meaning is “rich,” as the vectors of meaning cross and overlap. This is why they are used in artistic communication; the colors of painting are a connotative code. But connotative systems have the disadvantage—or perhaps the merit—that their meanings are ambiguous, and demand interpretation.
Could a code be made that was both clear and “rich,” and if so, could colors be used in it? Could we establish a color code, or perhaps several, that would serve for both scientific and artistic communication, thus doing away with the fateful divorce between scientific and “humanistic” culture? So stated, the problem shows its revolutionary impact. If such a color code were feasible, it would radically transform our cultural situation, affecting our thinking, our feeling, our whole perception of the world. It would alter our aistheton—would be an esthetic revolution.
Let us look at the “poverty” of denotative codes. Descartes asked, How can the clear and distinct structure of mathematical thought become adequate to the concrete compactness of the objective world? How can the “thinking thing” (res cogitans) become adequate to the “extended thing” (res extensa)? His answer was, Through analytical geometry, which to him was the only means for the gaining of scientific knowledge. The method was improved by Leibniz’s and Newton’s invention of the calculus, which was intended to stop up the intervals between the numbers by “integrating the differentials”—by producing a code that could express variability and change. This code, then, was both clear and “rich,” and people believed that it would make the world newly accessible to knowledge. One of the reasons our optimistic grandparents believed in “progress” was that everything had become codifiable in differential equations. (This, I would argue, was the true basis of 19th-century optimism.) But the optimism didn’t last, because to apply such equations, to use them to solve problems, it was necessary to renumerize them—to translate from the symbols of higher mathematics into what are usually called natural numbers, a tedious and lengthy task. (It may take longer than the human life span.) This is why computers were invented: to “calculate” equations. And this is the true reason for our contemporary pessimism about “progress”: even working up to computer speed, we cannot hope to live long enough to solve all the problems.
We should also consider the curious fact that thinking in the occidental tradition is mostly verbal. The problem that Descartes was trying to solve was one of adequating fundamentally verbal thought (“concepts”) to the world. This was because he saw the “thinking thing” essentially as a “speaking thing,” a thing that articulated itself through the alphanumerical code. It never occurred to him that one could think nonverbally—for instance in colors. Of course, it is easy to explain why so much of our thinking is verbal. Since our body’s organs allow us easily to codify airwaves into phonemes, speaking comes “naturally” to us (though it is an open question whether speech is a “natural” human faculty or a “cultural” one). Other species, however, have organs that allow them to codify colors. Some cephalopods, for instance, may change the color of their skin, producing various spots of different hues. They control each spot through their central nervous system, and there is no question but that they use this faculty to communicate; they dispose of a color language.
But we can do the same, and indeed we have done, at least since Lascaux, or since we began painting on cave walls. We are perfectly capable of thinking in colors, and of thinking nonverbally (illogically). But our color codes have so far been mostly connotative, and therefore of little value for communicating scientific knowledge. If we were to establish more denotative color codes, would that affect Descartes’ problem of adequating the thinking thing to the extended thing? What sort of knowledge would a color thinking convey, and generate? Would it justify a renewal of optimism?
Today, a fractal equation can be fed into a computer, where it is digitally transcoded, then “numerized” and computed in the form of curves and surfaces on the screen. Those shapes may be adequated to colors: the computer commands a palette of almost infinite variation. What has happened here is that numbers have been chromatically transcoded. A colored image of a fractal equation—let’s call it a “Mandelbrot monster,” after one of the originators of the science of fractals—is both a model of scientific knowledge (it is as clear and distinct as the code of numbers) and a model for esthetic experience (it is rich in meaning, like a work of art, which indeed it is). In proposing this kind of color code, we have lifted both scientific knowledge to the level of esthetic experience and artistic experience to the level of scientific knowledge. And we have eliminated the distinction between art and science. What we are doing here is thinking scientifically in colors.
Open any issue of Scientific American and you’ll see other examples of the codification of color to convey exact knowledge. Computer simulations of nuclear, chemical, and physiological phenomena come to mind, and also the tinting of photographs taken from satellites to show crops, the weather, and so forth. What is lacking in all these efforts, however, is a satisfactory cultural theory of colors. As long as we lack such a theory, the idea of a color code both clear and “rich” enough that in the future people will be able to communicate through it (as well as or even instead of through words) remains utopian. This is one of the reasons for a project under consideration to build a “House of Color,” a Casa da Cor, in Brazil, in the city of São Paulo—a place where a cultural theory of colors might be elaborated. There is as yet no consensus among the scientists, artists, philosophers, and scholars of communications who collaborate in the project as to how such a theory is to be formulated. This, of course, increases their feeling of adventure.
The divorce between the sciences and the arts grows partly from the contempt in which science holds everything not exact, partly from the artist’s contempt for the supposed barrenness and poverty of scientific reasoning. If colors could be used as codes for exact communication, those prejudices would disappear. The heart has reasons that reason ignores, and reason has a heart that the heart ignores, and only a unification of the two can really develop the virtualities dormant within all of us. Color may be a place where those two can meet, and result in a new culture.
Vilem Flusser is a teacher of communications at São Paulo University and at the Ecole Nationale de la Photographie, Arles. He has written various books on modern communications. He contributes this column regularly to Artforum.

