The starting point is the study of color and its effects on men.

—Wassily Kandinsky, Concerning the Spiritual in Art, 1912

The study of color—what it is, what it means, how best to organize and display it, and especially, the question of what makes combinations of colors pleasing—has a long history. The search for answers to these questions has produced an enormous library of writing known as color theory. Included within it are color-classification and color-order systems, color dictionaries and atlases, diagrams and encyclopedias. This writing covers color as science, color as language, color as poetry, color as instruction, color as art.

With the exception of the very earliest writings, the first concern of color theorists has been to find a way to organize and present colors in a format that is both comprehensive and logical. All start with the same material—there are no “new” colors—but organizational concepts arise from very different disciplines: from philosophy, from the arts, from mathematics, from science, from industry. As a result, it is not unusual, for example, to look for a definition of “primary colors” and find three different answers.

Each system of color-order is unique, and each seems at first to call for a separate truth, a format all its own. But there are common patterns within the many competing theories of color order. Rather than individual systems being wrong or right, each has chosen a different area of emphasis, and nearly all reinforce each other at the fundamental level. For purposes of thinking, for identifying color qualities and arranging them into a logical format, it is perfectly possible to structure a universally acceptable color-order system.

The second major concern of color theorists has been to identify those factors that make different colors pleasing in combination, to find a factual basis for determining color harmony. History, observation, and plain common sense suggest that as a practical matter there are just too many variables to establish absolute “laws” of color harmony. But within a well-constructed color-order system it is possible to identify guidelines for achieving color harmony that are consistent, understandable, and practical.

Setting the Stage

The earliest known writers on color were Greek philosophers. Intrigued by the elusive nature of color, they sought to establish its place and meaning in the larger universe. To the ancient Greeks, beauty and harmony were aspects of mathematics. They postulated that beauty, and by extension color harmony, is a natural result of mathematical order and that the two are therefore inextricably linked. Mathematics is precise, color is ephemeral; conjoined they offer control of an elusive topic. So powerful is the concept that beauty and mathematics together form a basis for color harmony that it has persisted from the earliest writers to the present day.

Pythagoras (c.569–490 BCE) is credited with originating the concept of the “harmony of the spheres,” a mathematical theory in which the planets are separated from each other by intervals corresponding to the harmonic lengths of strings, and therefore give rise to a beautiful musical sound. This ideal was extended to include forms and colors corresponding to the musical scale. Intended in its time to demonstrate the all-inclusiveness of the universe and an overriding wholeness in nature, it is a proposition that still resonates today.

Aristotle (c. 384–322 BCE), the most influential of the earliest writers on color, addressed it from both philosophic and scientific standpoints. His premise that all colors derive from black and white, or darkness and light, was accepted as fact until well into the eighteenth century.

Renaissance writers, including Leonardo da Vinci (1452–1519) and others before and after him, wrote on aspects of color that ranged from the practicalities of mixing pigments to the philosophical and moral meanings of colors. But writers on color were few, and color remained a topic of narrow and specialized interest until the eighteenth century, when, as the result of experiments by Isaac Newton, it was swept into the mainstream of philosophic and scientific thought.

The Beginnings of Color Theory

During the eighteenth century in Europe, a historical period known as the Enlightenment, or the Age of Reason, there was a fresh and vigorous search for rational, rather than mystical, explanations for all kinds of natural phenomena. People began to believe in the existence of irrefutable laws of nature. There was an assumption that there were natural laws for everything, including laws for combining colors, and that these laws, like the law of gravity, only awaited discovery. This search for absolutes determined by science was, in its way, as rigid and uncompromising as the demands of absolute faith that preceded it. Only the source of authority had changed, from God and his earthly representatives, the clergy, to reason and its earthly representatives, men.

The intellectual world of the eighteenth century was quite fluid. People didn't think of themselves as writers, biologists, or mathematicians but as “natural philosophers,” “theologians,” or “geometricians,” all with wide-ranging and overlapping areas of interest. Philosophers and literary figures wrote confidently, if with dubious expertise, on all kinds of scientific and philosophical topics. Others, poets poised at the edge of the sciences, sought a rational basis for the nature of beauty itself and, as a corollary, color. In this way the “behavior” of colors could be explained and predicted, and the mystery of observed color phenomena mastered through an understanding of natural laws. The search for laws of color harmony was simply one part of the sweeping intellectual ferment of the time.

Two themes dominated eighteenth-, nineteenth-, and early twentieth-century color study. The first was the search for a comprehensive color-order system, including an appropriate format for visualizing it. Once in place, that system could become a field in which the all-important search for laws of color harmony could take place. These treatises, dating from the late eighteenth century and continuing today, make up the collective study known as color theory. Just as there are classics in literature, there are classics in color theory. Two towering and very different figures dominate the beginnings of this discipline: Isaac Newton (1642–1727) and Johann Wolfgang von Goethe (1749–1832). Their observations remain the foundations of color theory today.

Isaac Newton, working at Cambridge in the late 1690s, first split sunlight into its component wavelengths by passing it through a prism. Newton observed that as each wavelength enters a prism it bends, or refracts. Glass, the material of the prism, slows each wavelength down at a slightly different rate so that each emerges as a separate beam: a distinctly different color.

Newton identified seven spectral hues: red, orange, yellow, green, blue, indigo (blue-violet), and violet. He then recombined the separated beams with a lens and reconstituted white light. From this he hypothesized the nature of light and the origins of perceived color. He published his results, entitled Opticks, in 1704. Newton's conclusion that light alone generates color remains a basis of modern physics and today—three hundred years later—of the screen display.

Many people cannot detect indigo as a separate color of light between blue and violet. There are a number of possible explanations for Newton's choice of seven hues for the spectrum of light. Newton was a genius, but also a product of the seventeenth century. He may have elected to include seven colors because that number corresponded to the musical notes of the diatonic scale. Mysticism was a great part of Newton's time, and mystical properties were associated with the number seven. Perhaps he had unusual visual acuity in the blue-violet range. Whatever the reason or reasons, the seven hues of Newton's spectrum remain the standard of physical science in ongoing recognition of his discovery.

Although the spectrum of light is linear, Newton also originated the concept of colors as a continuous experience. He diagrammed the seven hues as a circle, linking spectral red and violet. This first known illustration of colors as a closed circle appears in the 1704 edition of Opticks.

Newton's contemporaries viewed Opticks as a work on the nature of color, not on the nature of light. By the time of his death in 1727, interest in Opticks was widespread and the ideas in it had generated tremendous controversy all over Europe.

During this same period, artists and artisans were considering color from a wholly different direction. They were not concerned with the study of color as an abstract idea or a visual experience. Instead, they sought to resolve the difficulties found in mixing two or more colored substances together to achieve new and reliably predictable colors. Jacques Christophe LeBlon (1667–1741), a French printmaker, was the first to identify the primary nature of red, yellow, and blue while mixing pigments for printing. LeBlon's treatise Coloritto (c.1730) presented the concept of three subtractive primary colors, and his work attracted a great deal of attention and acceptance.² Unlike Newton's color theories, which addressed colors of light, and Goethe's later ones, which included ideas about perception, emotion, morals, and aesthetics, LeBlon's observations dealt with practical reality. His work remains a theoretical basis of printing to this day.

Moses Harris (1731–1785), an English engraver, used LeBlon's three primaries to produce the first known printed color circle (c. 1766). Harris, also addressing artists' and printers' colors, was the first to publish them as an expanded circle of relationships—a true visualization of color organization. Harris believed that red, yellow, and blue were the most different from each other and should be placed at the greatest possible distances apart on the circle. Harris discarded Newton's indigo and created an expanded color circle based on equal intervals of color and multiples of three; an organization later adopted by the man who is arguably the preeminent color theorist of the late eighteenth and early nineteenth centuries: Johann Wolfgang von Goethe.

Color and Controversy

Goethe was fascinated by color. He was familiar with Newton's theories of color but strongly opposed them and bitterly resented the acceptance of Newton's ideas. He wrote, furiously, of Newton: “A great mathematician was possessed with an entirely false notion on the physical origin of color, yet, owing to his great authority as a geometer, the mistakes which he committed as an experimentalist long became sanctioned in the eyes of a world ever fettered in prejudices.”⁴

Goethe spent a great deal of energy trying to prove that Newton was wrong, publishing his first treatise (of a lifelong series intended to refute Newton's hypotheses) in Announcement for a Thesis in Color in 1791. Goethe viewed colors not as light, but as an entity of their own, as experienced reality. His difficulties with Newton's ideas are evident in his own words. Newton's theory, he says, “does not help us to perceive more vividly the world around us” so that “even if we found a basic phenomenon, even then, the problem remains that we would not want to accept it as such,” and “things which belong together according to our senses often lose their connections once we look into their causes.” He scolded Newton sharply for his views: “The natural philosopher should leave the elementary phenomena in their eternal quietness and pomp.”⁵ Goethe's response to Newton, although highly emotional, is also pragmatic. He is saying, “What you say may or may not be true, but it is not useful in real life.”

Like Newton, Goethe was both a genius and a child of the Enlightenment. Unlike Newton, however, he wrote with a sort of shotgun approach, aiming his considerable intellect at a topic, letting fly a lot of ideas, then turning without pause to fire again in a different direction. For today's readers, Goethe's writing includes a lot of unintended humor, like discussion of the color sensibilities of earthworms and butterflies. Associations of color and beauty with morality were also a part of Goethe's treatises. There were sinful colors and chaste ones. “People of refinement have a disinclination to colors,” declares Goethe, firmly—a bias that will appear repeatedly in the writings of color theorists well into the twentieth century. He associated moral character not only with the choice of colors in clothing but with skin color as well.⁶

Despite his freewheeling digressions, Goethe's observations were wide-ranging and seminal. He and his contemporary Philipp Otto Runge (1777–1810), a German painter, shared in conceptualizing what are now called complementary colors. He called them, with enormous insight, “completing colors.”⁷ Goethe also reported extensively on the phenomena of simultaneous contrast and afterimage. He recognized that no pure color exists except in theory and characterized the principal contrasts of color as polarity (contrast or opposition) and gradation (intervals). Although other artists and writers expanded Goethe's ideas and added new material, Goethe's observations were so wide-ranging and fundamental that almost every concept in modern color study can be found in his writing.

Goethe's most familiar contribution to color study is the six-hue color circle. Although Goethe believed that there were only two primary colors, blue and yellow,⁸ and that all colors derived from them, LeBlon's red-yellow-blue primary-color concept prevailed, and Goethe's completed color circle reflects that three-primary convention. We know it today as the basic artists' spectrum: equal arcs of six colors: red, orange, yellow, green, blue, and violet. Its elegant simplicity can be described as perfect visual logic.

French dyer Michel Eugene Chevreul (1786–1889), like Le Blon before him, addressed color from a practical viewpoint. As master of the Gobelin Tapestry Works, Chevreul found difficulties with black dyes, which seemed to lose their depth or darkness when placed next to other colors. Chevreul accepted the three-primary-color theory. He observed and reported at length the phenomenon of simultaneous contrast, and his 1839 treatise The Principles of Harmony and Contrast of Colors and Their Applications to the Arts (De La Loi du Contraste Simultane des Coleurs) was a profound influence on the impressionist movement in painting.

Goethe's six-hue spectrum of subtractive color remains the convention for artists; Newton's seven-hue model of visible light remains the scientist's spectrum. The battle between Newton's and Goethe's color theories was a major schism in the history of ideas. It was unnecessary. Both theories are valid, but each describes a different reality:

• Newton was looking at causes.
• Goethe was looking at effects.

Before the advent of digital design, students engaged in the sciences were not usually the same as those who pursued the visual arts, and the differences between the two systems of color rarely conflicted. Designers in the past, like Goethe, worked with color from the evidence of their senses. They dealt with effects, not causes, and science was relegated to a back seat in the studio workplace. The medium of today's studio is light, and designers must work within—and between—the two realities.

The Scientific Model: Color Gets Organized

Chevreul and Goethe were gifted observers and obsessive chroniclers. Most of the late nineteenth- and early twentieth-century color theorists who followed them worked instead from a scientific model, codifying their observations into rigidly formal systems. These theorists wrote on color as a discipline, as fact, as scientific truth. The stress was on rules, control, and order; the goal was to create a comprehensive color-order system and to find within it immutable laws of color harmony.

Early color-order systems displayed colors as two-dimensional charts: rectangular, triangular, and circular. The organization of color as three-dimensional model, conceptualized by earlier writers, was brought into widely circulated realization by American Albert Munsell (1858–1918.) In A Grammar of Colors, published posthumously in 1921, Munsell proposed a “color tree” with infinite room for expansion. Munsell's color space is constructed as horizontal arms of hue that rotate around a vertical axis of value from black to white. The end of each “branch” is a saturated hue that moves in intervals of diminishing chroma toward the central axis until it arrives at its equal-value gray. Hue intensity is reduced at each step, but value remains uniform along each horizontal branch.

In Munsell's theory every possible color cannot be shown, but each has an assigned place on an alphanumeric (letter and number) scale. Munsell believed he was providing a comprehensive color-order system, stating, “Naturally, every point (of color) has a defined number” so that “there can be no new color discovered for which a place and a symbol is not waiting.”⁹

But a pure hue can be reduced in saturation in two ways. It can be diluted by the addition of gray, as Munsell illustrates, but also (and more usually) by the addition of its complement. Subtractive complements change in both saturation and value at each step as they move toward each other. Instead of an achromatic gray where they meet, each pair of opposites arrives at a chromatic neutral that is logical for that pair alone.¹⁰ In the Munsell system, each hue is placed roughly opposite its complement but is independent of it. The entire range of muted hues that is created by the mixture of complements is absent. Munsell might have illustrated color space as two trees, the second moving toward a center axis of tertiary colors in intervals of both saturation and value, and come closer to a comprehensive visualization of color space.

Like many early color theorists, Munsell included in his writing distracting associations of colors and morals. Following Goethe, Munsell associated color choices with character and morality, declaring that, “Quiet color is a mark of good taste,” and “If we wish our children to become well-bred, is it logical to begin by encouraging barbarous (i.e., colorful) tastes?”¹¹ The Munsell system is still used in industry and in classrooms, but without much of the original commentary.

Munsell's contemporary, German chemist Wilhelm Ostwald (1853–1932), was a Nobel Prize winner who brought the concept of a color solid to full-blown theory in Color Science. Ostwald's later The Color Primer, with its eight-hue spectrum, became mandatory for color study in German schools and in many English ones and was an influence on artists of the Bauhaus movement.

Wilhelm von Bezold (1837–1907) and Hermann Ludwig Von Helmholtz (1821–1894) contributed scientific fact to the growing body of color writing. The psychology and physiology of color vision, even color healing, became areas of increasing interest to scientists. By the early twentieth century, color study had become an enormous and wide-ranging topic, positioned uncomfortably with one foot in the sciences and the other in the arts. It remained for the artists and designers of the Bauhaus, a design group founded in 1919 by German architect Walter Gropius, to make the definitive break between the study of color as art and the study of color as science.

The Bauhaus group brought the study of color to a level of attention not seen since Goethe's challenge to Newton. Feininger, Klee, Kandinsky, Mondrian, Itten, and Albers, master/students of color and color theory, approached color from new directions with intelligence, wit, and energy. Although inevitably some elements of the older, quasi-scientific style persisted in their work, Bauhaus color study dealt principally with art and aesthetics. Light remained in the realm of physics; chemistry and engineering took over the nature of colorants; and psychology, physiology, and medicine became the arena for perception.

Johannes Itten (1888–1967) followed Goethe in exploring color as a series of contrast systems and opposing forces. He theorized seven contrasts of color based on perception alone: contrast of hue, value, saturation, warmth and coolness, complementary contrast, simultaneous contrast, and contrast of extension (area). Itten codified color harmonies as a series of chords based on the complementary relationship and diagrammed them as geometric forms.¹² Although these chords are mathematically based, Itten's approach to color theory was notably less rigid than many that preceded it. His focus was as much on color perception and relationships as it was on mathematical constructs. Significantly, one of his major works is titled The Art of Color.

Color by the Numbers

Color-order systems were the first concern of theorists because a strict organization of colors would create a structured field in which to search for laws of color harmony. The primary focus of that search was on the relationship between hues, with value and saturation as secondary considerations more lightly touched upon. Each writer who sought laws of harmony concluded, in one way or another, that the basis of color harmony is order, and more specifically, that harmony lies in a balanced relationship between complementary hues. Goethe repeatedly characterizes color harmony as balance. Johannes Itten says that “The concept of color harmony should be removed from the realm of subjective attitude into that of objective principle.”¹³ Ostwald referred to “This basic law—Harmony = Order.”¹⁴ With his structured charts, Munsell could conclude, “What we call harmonious color is really balance.”¹⁵ There was a rare but complete concurrence of opinion: balance between complementary colors was the first principle of color harmony.

The ancient ideal of mathematical balance was so much a part of the search for laws of harmony that in nearly every construct hues were associated with numbers or geometric forms. Two examples are representative of the mathematical-balance theories of harmony based on the complementary relationship. Philosopher Arthur Schopenhauer theorized that equal light-reflectance in spectrum colors is inherently harmonious. Using Goethe's color circle as a basis, he suggested a scale of luminosity for each of the six pure hues. Each color is assigned a number representing its light-reflectance (or value) in relation to the others.¹⁶ Yellow, the most luminous, is assigned 9, the highest number. Violet, the darkest of the pure colors, is assigned 3. Red and green are equal in value, and blue and orange are placed relative to the others.

The total of all of the numbers added together is 36, or 360º: a full circle. When each pair of complements is added, they total 12, or a 120° arc on a circle. Each pair of complementary colors thus occupies one-third of the color circle, a perfect mathematical balance.

This color circle recognizes the disparities in value between the saturated colors, but the conclusion it draws is deceptive. A patch of saturated violet that is three times the area of a patch of yellow does not necessarily reflect the same amount of light as the yellow. The light-reflecting value of colors is not a function of their area. What it does illustrate, very effectively, is one way in which we sense value differences between pure colors. Schopenhauer's theory can be illustrated as striped T-shirts. In order for each shirt to be harmonious, the red and green one must have equal-width stripes, the violet and yellow one must have violet stripes three times as wide as the yellow, and the blue and orange must have blue stripes twice as wide as the orange.

Johannes Itten superimposed geometric forms over a twelve-hue artists' spectrum to demonstrate what he called “harmonious chords,” calling them, “systematic color relationships capable of serving as a basis for composition.”¹⁷ Each color chord illustrates complementary colors in some measurable proportion. The chords are described as dyads, triads, tetrads, and hexads, with the geometric points locating the “notes” of each chord. An equilateral triangle identifies the primary hues yellow, red, and blue as harmonious; the same holds true for the secondaries green, orange, and violet. Ittens's split complements are an extension of the complementary relationship, created by superimposing an isosceles triangle over the color circle. Yellow, for example, is complemented by red-violet and blue-violet. Squares and rectangles performed the same sort of magic, and any of the geometric forms can be rotated within the circle so that harmonious hue relationships are maintained at any point. But each form is a variation of the same idea: the harmony of three primary colors presented as opposites.

A New Perspective

Color numbering systems have great value when used to communicate information between individuals who have reference to the same set of standards. Equally useful for additive or subtractive colors, they are essential for specifying colors in Web design, or charts for paints, inks, or countless other products. The many systems of letters, numbers, and formulae for colors can be essential as production aids, but numbering systems are a distraction on the path to an understanding of color. It remained for Itten's colleague at the Bauhaus, Josef Albers (1888–1976), to make the final break with the numbers-based color-order tradition.

Albers fled Nazi Germany in the early 1930s and brought his teaching methods to Yale. He became the most influential name in color theory in the United States, but his 1963 book Interaction of Colors contained nothing like the usual charts or systems. Albers did not contribute to ideas of color order. He had a new role to play.

Albers taught that true understanding of color comes from an intuitive approach to studio exercises. He stressed the instability and relativity of perceived colors and the power of visual training. At the same time, he taught that even within this unstable field, effects can be predicted and controlled. In Interaction of Colors (1963), Albers casually discounts the generations of theory that preceded him: “This book . . . reverses this order and places practice before theory, which is, after all, the conclusion of practice.”¹⁸ Albers was not the first to recognize that the visual experience, more than conscious choice, determines how we perceive colors, but he was the first to assert the primacy of the visual experience over structure or intellectual considerations. For Albers, the visual experience, not theory, was paramount.

The Albers intuitive approach dominates American color education today. Detached from its background in color-order systems, it is not as accessible an approach to teaching color as it could be. The intuitive approach makes infinitely more sense when it follows an understanding of what color-order systems are about. By learning first to discriminate hue, value, and saturation and mastering the concept of intervals, or steps between colors, students acquire skills that make the Albers exercises comprehensible from the start. Color-order systems and the Albers intuitive approach are not alternative ways to study color, nor are they competitive. The first leads seamlessly to the second, and together they embrace an understanding of color without limits or gaps.

The late twentieth century saw the focus of color study shift from philosophical inquiry to a greater interest in psychological and motivational effects of colors. The entire industry of color forecasting, for example, is devoted to determining current and future consumer preferences in colors and color combinations. At the same time, color theorists continue to search for absolutes. There is an enduring assumption—or perhaps, a wistful hope—that those elusive, timeless, and absolute laws for pleasing combinations of colors really do exist and simply await discovery.