1. Color Facts and Color Theories

Color is so constantly in evidence in our daily lives that we are inclined to give it almost no conscious at­tention. We merely accept color, as we do sunshine and shadow, failing not so much in our appreciation of its beauty — for we all like color — as in a full realization of what an important part it plays in our daily lives. Color to many of us is a thing to admire consciously or openly only now and then, when particularly called to our attention, as in a sunset or a striking painting. Actually, how­ever, even though we do not real­ize it, color influences us during practically every waking moment.

For, although color in itself is not absolutely essential to human life, as is shown by the fact that the achro­matic vision of the totally color-blind person apparently meets his needs fairly well, it is still true that our ability to see color all about us adds inestimably to the richness of our existence. There is, undoubtedly, a growing recognition of the important part which color plays in almost every branch of our emotional and spiritual lives. We are more inclined to cheerfulness on bright, colorful days than when the sky is gray. We are more contented in harmoniously colored rooms of reasonably distinct hue than in those which are drab; on the contrary, we are disturbed by interiors which are gaudy and crude. We admire clothes of beautiful color and like to have colorful things about us such as books, flowers and pic­tures. We like the out-of-doors for its green trees, blue skies and pur­ple hills. Even our food is more appetizing when it is attractive in color than when it is neutral in tone. As color affects our happiness, it in turn affects our health, so its effects are far reaching.

Not the least of its merits is that color serves us in many practical ways. It aids us, for instance, in distinguishing one object from an­other at a glance, as is illustrated when we go to the bookcase to select some familiar volume. It helps us to know whether fruits or vegetables are unripe, ripe or spoiled; whether food is raw, sufficiently cooked or overdone; whether objects are ex­tremely hot or cold. It guides us in judging many conditions of sickness and health. It aids us in determining comparative distances. A moment's contemplation brings to mind numer­ous ways in which color serves us. There is scarcely a phase of existence not affected by color in some way.

Color becomes so much a part of us, despite our customary lack of conscious appreciation of it, that should we suddenly become unable to distinguish one hue from another, we would immediately realize our deep loss. The world would offer, instead of its accustomed harmony of many colors, much the neutrality of a black-and-white photograph. It would be a gray world indeed, both figuratively and literally.

Just as color interests and pleases us today, so it apparently affected primitive man. At least, we have ample evidence of the constant use of pigments from the earliest known times. Not only was the humble home, together with its implements and utensils, embellished in gorgeous hues, but its inhabitants employed colors lavishly both on their clothing and their bodies. The male of the species, contrary to our present custom, went forth, especially when in battle array, dressed, accoutered and adorned in the most vivid color­ings imaginable, doubtless to his own great delight, and supposedly to the consternation of his enemy.

If from this early starting point we should trace the gradual progress of mankind, we would find this same love of color manifesting itself over and over again. At the time of the ancient Egyptians, Persians and As­syrians, for instance, color was still used in abundance, yet with an increased restraint and appreciation consistent with the development of civilization as a whole.

From those days of thousands of years ago to the present, color has continued to occupy the attention of man, who has ever sought to wrest its secrets from nature. With the advance of science, the speculation of the ancient has given way to the intelligent research and experimen­tation of the trained investigator. Especially during the last century or two have physicists, physiologists, and more recently, psychologists stud­ied the problems of light and color and the processes of vision. Nor have the chemists been idle in the meanwhile, for under them a sound advance has been made in the dis­covery and perfection of pigments. The colorists in various fields have done their part by putting these pig­ments to all sorts of uses, seeking at the same time laws regarding their harmonious application.

In view of the united efforts of so many serious investigators over so long a period of time, the student entering upon any phase of color study usually expects to find the entire subject thoroughly understood and placed on a truly scientific basis, with exact laws determined, perhaps comparable to those of music. It is often a great surprise for him to learn that, although marked progress has been made in every department of color investigation, nature still withholds many of its secrets. In fact, years may yet elapse before light itself and color vision, which permits us to see colors all about us (for color is only a matter of vision, as we shall explain more fully a bit later), are thoroughly understood. Man, too, despite any claims to the contrary, progresses slowly in his attempts to discover definite and infallible laws regarding the concord­ant employment of color in such pigment forms as paints, inks and dyes. It is more than possible that such laws may never be found.

When the student first comes to a full realization of the fact that the employment of color is not a thing which he can learn to any great extent by rule — that there are few precise and easily applied laws for his guidance — he is quite sure to wonder just how he will manage to make satisfactory progress.

A bit later we plan to offer a word of advice as to what course he should follow. Enough now to assure him that, despite this condition that seems in certain aspects a bit puzzling or chaotic (or will, at any rate, by the time the next few pages have been read), his path will by no means be as difficult as he might expect. As a preliminary to this advice, we now propose to present a short discus­sion designed to give him the back­ground necessary for any serious approach to color study.

To Sir Isaac Newton, working in the 17th century, is attributed the discovery that light consists of many rays, each of which, when allowed to impinge separately upon the retina of the human eye, produces the sensation of a distinct color, the fusion of all the sensations generated by the mixture of rays giving the sen­sation of white. Color, therefore, was shown to be a sensation — a matter of vision.

Until Newton's time it was com­monly believed that color was as much an inherent characteristic or property of any object as was its shape or texture. It is not easy for us, even now, to realize fully the established fact that the red of an apple is not an innate quality of the apple, strictly speaking, but that we merely see an apple as red because it has the property of absorbing some rays of light while reflecting others to the eye — a matter to which we shall presently return.

Light and color are essentially one, so the student who cares to make anything approaching a complete investigation of color should lay a foundation by grounding himself thor­oughly in a knowledge of both the physical facts concerning light and the physiological and psychological effects of light, and its resultant color, on the individual. He can best do this by turning to some of the recog­nized books on the subject. One of the best we have come across is Ralph M. Evans' An Introduction to Color (John Wiley & Sons) which seems to cover the subject pretty thoroughly in regard to physics, phy­siology and psychology and also includes chapters on paints and pigments, and color in art, design and photography. The Optical Society of America has also produced an excellent volume on the various scien­tific aspects of color called The Science of Color (Thomas Y. Crowell). Although most of the material in this book is in the language of the scientist, there are two very helpful introductory chapters for the nonexpert.

In view of the availability of these and other such books for those who may wish to investigate this phase of color study more thoroughly, we shall offer here only a few funda­mental facts, stated so far as possible in non-technical terms.

Light is said to come from its source as a wave motion, the waves traveling at the remarkable speed of approxi­mately 186,000 miles a second. The sensation known as color is pro­duced by the action of these waves of light upon the human eye. The waves vary in length; these variations in wavelength produce different sen­sations in the eye corresponding to the different hues with which we are familiar.

Newton performed a most interest­ing experiment in this connection which anyone can easily repeat. In a darkened room he admitted a beam of sunlight through a slit in a window shade and allowed it to traverse a prism. This separated or decom­posed the light into a long line of colors, imperceptibly graded one into another, similar to a rainbow. This separation of white light into its elements is called dispersion. The resulting band is known as the spectrum. The colors of the spec­trum arrange themselves in the order of their wavelengths, the long waves being less refracted (that is, bent as they pass through the prism) than the short. Starting with the red, which has the longest and slowest vibrating waves of any color visible to the human eye, innumerable colors follow, the most prominent being, in this order, red, orange, yellow, green, blue, indigo and, finally, violet, which, has the shortest and most rapid waves of any visible color. This experiment of Newton's is illustrated in Figure 1.

These light waves which are vis­ible to the person of normal eyesight constitute but a small proportion of all the light rays which exist. We are color-blind to waves longer than about 0.0007 millimeters (the approx­imate length of red rays) or shorter than about 0.0004 millimeters (the approximate length of violet rays), many others, including the infrared and ultraviolet, being invisible under customary conditions.

Newton followed his experiment of separating white light into the prismatic spectrum by a second, in which he passed a portion of this colored band through an aperture in another screen, permitting it to trav­erse a second prism. As he found no additional change of color he was convinced that monochromatic light could be no further decomposed. Newton also demonstrated that not only can white light be decomposed into many colors by a prism (such experiments are often carried out today with the spectroscope or simi­lar apparatus), but that these colors can be recombined into white light. This can be proved by impressing such colors on a second prism, or by receiving them from the original prism onto mirrors or lenses so curved as to convey all to a single spot where they will reunite to form white.

Figure 1. This diagram of Isaac Newton's experiment shows how a beam of white light, passed through a prism, is refracted and broken up into the colors of the spectrum.

Thus, it was long ago shown beyond reasonable doubt that light is the source of color, and that white light, which seems so simple and pure, is, in reality, made up of vary­ing rays, each capable of producing the sensation of a distinct hue. It is obvious, then, that when light is present, color is present; when light is absent, color is absent. It follows, too, that the nature of light influ­ences the nature of color; objects look different under daylight, incandes­cent light, fluorescent light, colored light, etc. In experiments such as we have mentioned, the light from the sun is usually considered as white; actually, as it reaches us through the atmosphere, it is often far from pure.

With this as a background, let us consider why one object looks red and another green. If we glance at a given object (excepting self-lumi­nous, fluorescent or transparent ones which would bring us into a discus­sion more involved than we need enter here), we are able to see it by the light cast upon it and reflected to the eye. It is easy to understand that, if the object is in strong light, it reflects much light and therefore appears bright; if in dim light, it reflects little and seems indistinct. It is not so easy to understand why one object appears red and another green until we learn that surfaces exercise a selective power on the light of the sun or other source of illumination, every surface decom­posing the particular light with which it is illuminated, absorbing some of the constituent rays while reflecting or scattering others in all directions. (We are here refraining from any consideration of the different kinds of reflection and reflective surfaces, and from a discussion of the ap­pearance of objects exposed to color­ed light.)

A red book, as it decomposes the light which falls upon it, absorbs or annihilates all the rays but the red; these are reflected, some of them reaching the eye, which instantly conveys to the brain, via the optic nerve, the sensation of red. A green book, on the contrary, has the power of absorbing all the rays but the green; these are the ones reflected. A white object is merely one which reflects a large percentage of the rays, including all colors so bal­anced as to give the effect of absence of color — white. A black object is one which absorbs nearly all the rays which reach it. A gray object absorbs some rays and reflects others, doing so without disturbing the relative proportion of waves as they exist in the light illuminating the object.

Few objects appear as of a single pure color, however, or absolutely white or black — hence this descrip­tion is far from complete. If one desires a more complete explanation of the whole matter, such books as Ralph Evans' Introduction to Color or the Optical Society of America's The Science of Color, both mentioned previously, should be consulted.

Now let us further consider our prismatic spectrum. If a prism is available, the reader should use it to project the spectral colors onto some suitable surface to see if he can gain the impression, as early investigators did, that some spectral colors are simple, whereas others are com­pound. (If no prism is available, the black-and-white diagram at Figure 1 will serve, to some extent, as a point of reference in the following discus­sion.)

Newton, over two hundred years ago, selected his famous seven steps of color (red, orange, yellow, green, blue, indigo and violet) as principal or fundamental. Later investigators thought him wrong because they found that, using only three of these colors, they could produce all of them. Sir David Brewster concluded after long experimentation with pig­ments and colored glasses (which apparently contained pigments) that light waves of three primary colors — red, yellow and blue — overlapped to form the spectrum. Because of his scientific prestige, this is usually called the Brewster theory, although it is probably of much earlier origin.

For a time, apparently, this theory was unchallenged, gaining quite gener­al acceptance both by scientists and colorists. Among its adherents was the famous Frenchman, M. E. Chevreul, whose findings, based on exhaustive experiments in color re­search, particularly as related to dyes (he was director of the dye depart­ment of the famous Gobelin tapestry works), still have a strong influence. Despite our improved knowledge of color in general, there is much of value to be learned about pigment application, even today, from his book, The Laws of Harmony and Contrast of Colours, published about a hundred years ago.

This general accord between scien­tists and colorists was short-lived, however. Early in the 19th century, Dr. Thomas Young conceived the theory that white light was composed of three primary bands — red, green and blue-violet (rather than red, yel­low and blue) — and that these could be mixed to produce any other color. According to this theory, which was little known until more fully devel­oped by Hermann von Helmholtz and James Clerk Maxwell, and today is generally known as the Young-Helm-holtz theory, there is present in the eye three groups of nerve fibers or photochemical substances. One group is mainly sensitive to red, one to green, one to blue-violet. Inter­mediate hues act upon at least two of the three groups. Yellow rays, for instance, affect the nerve fibers or photochemical substances sensitive to red and those sensitive to green at the same time, thus giving the sensation of yellow. So, according to this, yellow would not be a primary color, as in the Brewster theory, but a mixture of red and green. The sensation of white would result from equal stimulation of all three groups.

As there was no anatomical evi­dence of the presence in the eye of these three groups of nerve fibers as photochemical substances, the Young-Helmholtz theory, like that of Brewster, was based on the physical mixture of color. However, instead of the pigments used by Brewster, the experiments were carried on with spectral colors or with a color wheel with spinning discs, a mixing device used by Maxwell.

Even today, despite later theories concerning the perception of color, the Young-Helmholtz theory stands up well in tests of spectral color mixture. If, for instance, the spec­trum is projected, by a prism or otherwise, onto an opaque screen arranged with fine slits which permit the red and green rays alone to pass through, these rays can be gathered or made to unite or overlap on an­other screen, by means of additional prisms, lenses or mirrors, where they actually do appear as yellow. If to the yellow thus obtained, blue-violet rays are added, the result is white light. In other words, red, green and blue-violet rays of light actually do produce, in mixture, white light. (See Plate 1.)

This theory was disturbing to artists and colorists generally, as it did not work out with pigments as did the Brewster theory. Attempts to mix normal yellow from red and green pigments, for instance, proved fail­ures, so speculation became com­mon as to whether or not pigments and light followed the same laws.

Today, the physicist understands the reasons why pigments cannot give the same results in mixture as do spectral colors. It seems hardly necessary to go into them in detail here since they are extremely com­plicated, but we might point to the single fact that when one spectral hue is added to another, light is added to light (brilliancy to brilliancy), so that when all the spectral hues are merged, the result is bright, pure light. When a pigment of one color is added to a pigment of another color, however, each pigment having absorbed or annihilated some of the light illuminating it, dullness is, in a sense, added to dullness, the final mixture of many pigments always being neutral gray or black.

In recent years, other theories re­garding the perception of color have been developed which suggest that, in addition to Brewster's pigment primaries and the Young-Helmholtz light primaries, there is a third set of fundamental colors, or, perhaps more accurately, color sensations.

Ewald Hering, a German physiol­ogist of the late 19th century dis­agreed with the Young-Helmholtz theory that there were nerve fibers or photochemical substances in the eye sensitive only to red, green and blue-violet, with all other color sensations the result of simultaneous stimulation of two or more of these. Hering ad­vanced the theory that there were three photochemical substances in the eye (he had no more proof of their exact nature, or even existence, than Brewster, Young or Helmholtz), each of which could be stimulated by a pair of opposite or complemen­tary light sensations: red and green; yellow and blue; black and white.

These are also the paired prima­ries in an interesting theory put forth by Christine Ladd-Franklin, who be­lieved the eye evolved from an ele­mentary organ capable only of dis­tinguishing light and dark (black and white), to an intermediate stage in which blue and yellow could also be distinguished, and finally to its present state. According to this theory, eyes with red-green color­blindness have not fully developed to what we now consider normal. Total color blindness indicates the eyes did not get beyond the light-dark stage.

Both the Hering and the Ladd-Franklin theories are much more complicated than these brief expla­nations might suggest. It does not seem necessary, however, to go into them more fully here. We should mention, however, that red and green, blue and yellow, black and white have been, in recent years, accepted by psychologists as the fundamental colors in terms of vision and are now generally known as the psycho­logical primaries. They also prove out rather consistently in medial or visual mixture, as can be shown by the Maxwell discs which make it possible to experiment with a com­bination of light and pigment mixture. The Maxwell discs were first used by James Clerk Maxwell to demonstrate color mixture (see Figure 2). Colored discs, slit radically from center to circumference, can be fitted together in any combination or proportion.

When two or more colors are com­bined and rotated at high speed on a spindle such as a spinning top or an electric fan from which the blades have been removed, they merge to appear as one, the effect of mixture being obtained through persistence of vision. (The same phenomenon can be observed by spinning almost any child's toy top and noting what happens to the colorful surface de­signs as the top spins.)

 

Figure 2. The device shown here is an adapta­tion of the Maxwell color wheel and discs. Colors are mixed visually; the primaries are red, yellow, green, and blue.

This method of color mixture was for many years more confusing than helpful. Although the fascinating little device blended colors to pro­duce innumerable hues, it never quite proved out with either the Brewster or Young-Helmholtz theories of color mixture. Normal blue and normal yellow do not spin out to green, as an adherent of the Brewster theory would expect, but to gray. On the other hand, normal red and normal green also produce a neutral tone rather than the yellow of the Young-Helmholtz theory.

Now that red and green, blue and yellow, black and white are generally accepted as the psychological pri­maries, the value of the Maxwell discs is more clearly understood. They do not obey the laws for pigment or light mixture, but rather those for visual or so-called medial mixture, which seems to be a combination of both, the eye mixing the reflected light of the discs.

Although normally of little value to the painter, the Maxwell discs are quite useful in some phases of color work, particularly in conjunction with some systems of color notation.

It is interesting to note that the psychological primaries include both pigment and light primaries as well as black (which in one sense is the absence of light, but in another might be thought of as the sum total of mixing pigment primaries) and white (the sum total of light primary mix­ture). Another point worth thinking about in this connection is that, in mixing the light primaries to create secondary, red and green produce yellow; green and blue-violet pro­duce turquoise or cyan blue; red and blue-violet produce magenta red.

Plate 1. (See page 31.) These two groups of color circles demonstrate the difference between pigment color mixture (top) and light or spectral color mixture (below). Pigments reflect some light, absorb the rest. Thus some light or brilliance is subtracted by each pigment in a mixture. When the three pig­ment primaries — red, yellow, and blue — are mixed together, the result approximates black. Here a magenta red, a clear yellow, and a cyan blue were used; these are the three colors that in appropriate mixtures produce the most complete range of hues. When colored light is added to colored light, brilliance is added to brilliance. A mixture of spectral colors is brighter than any individual color. A mixture of the three light primaries — red, green, and blue-violet — produces white light.

These light secondaries are almost identical with the pigment colors usually accepted as primary. When we mix our pigment primaries to create secondaries, however, the re­sults are orange, purple and green, green being the only light primary of the three. There would seem to be a correlation of some kind between the light and pigment primaries, but, if there is, its exact nature seems, so far, to have eluded the most deter­mined investigators.

Of course, the physicists, physiol­ogists, psychologists and chemists — as well as colorists in many phases of industry and art — are constantly exploring all the aspects of the behavior of color and may one day solve its mysteries. In the meantime, the puzzle often seems to become more puzzling. For instance, Dr. Edwin Land, inventor of the Polaroid Land Camera, while carrying out a series of experiments relating to color pho­tography, discovered he could pro­ject a full-color image on a screen through black-and-white transparen­cies, using only two colored lights. His experiments, reported in the May 1959 issue of Scientific Ameri­can, raise many new questions on the nature of color vision. They may eventually lead Dr. Land or others to the key.

Meanwhile, what does all this mean to the student painter? Once he is aware of the fact that color is a com­plex subject that often baffles the most scientific minds, how can he best begin his own studies?

First, he can turn his back on all the puzzling things the scientists are discussing, at least for the time being. Accepting a few facts of proven worth such as outlined here, he can employ them as a basis for pigment experimentation, gradually learning to know color through using pigments in attempts to represent such effects of color as he sees about him. He will try to analyze color appearances, in other words, and endeavor to express them with his pigments by painting.

Since he is working with pigments rather than light, let him hold to Brewster's red, yellow and blue as his primaries, adding to them such other hues as seem to him most essential, according to his individual requirements.

Then let him experiment with these pigments, following such progres­sive exercises as we offer in this volume, secure in the knowledge that whatever he learns of color from such experimentation can be utilized later in all his color problems.

The student who thus elects large­ly to ignore the findings of the scientists, turning immediately to practical experimentation with brush and paint, can do so with the assur­ance that he is following in the footsteps of a vast host of artists who have successfully pursued a similar course before him. For even of the acknowledged experts in the field of color — experts who attribute no small part of their success in such professions as painting, architecture, interior decoration and industrial de­sign to their ability to use color well — many a man has acquired his grasp in what might seem an extremely haphazard manner, picking up an idea here and another there, exper­imenting, comparing and analyzing over a long period of time (perhaps with pigments, though possibly with building materials, fabrics, etc.) until he has accumulated a fund of color facts and developed an indefinable feeling for color — increased sensi­tiveness to and appreciation of it — which grows and changes with the years.

The second course open to the student is more difficult than the first, particularly if he is young or impatient. Certainly it is far less commonly followed. Before starting with pigments at all, he would make an effort to ground himself thor­oughly in the fundamentals of science as they relate to light and color. He would investigate such theories and opinions and laws as we have touched upon, which would involve reading many books (and doing some acute thinking as well), for we have introduced our reader to only a few of the intricacies and complexities of the subject.

It is evident that the student who conscientiously follows this latter course will have quite a delay before he gets to his consideration of pig­ments. Even then he will have ac­quired little knowledge directly appli­cable to his daily problems; he must still experiment and experiment, as every artist does. His scientific knowledge may even deter him from painting in the bold, free manner which is generally productive of the finest results.

Perhaps the best move of all is to compromise by combining these two courses, with emphasis mainly on pigment practice. It seems hardly wise to risk, just at first, the mental indigestion which would be almost sure to follow any attempt to straight­en out at once all the tangle of seem­ingly irreconcilable theoretical and practical matters. Possibly the begin­ner would do well to go ahead with his exercises with pigments for some time, undisturbed by anything else. Pictorial representation, being mainly imitative and taking its color schemes largely from nature, can be done successfully with little or no knowl­edge of the laws of light and spec­tral color. Later, he could investigate such of these laws as his pigment practice brings to his attention or his individual requirements seem to demand. He will need increased scientific knowledge if he turns to forms of creative art which involve the direct use of light itself — leaded glass, for instance. Theatrical design and window display work are even more complex, as lights and pigments are employed in combination. This volume, in guiding him through his practical work with pigments, directs attention now and then to some of the contacts which he can advan­tageously make between the two fields of art and science.

Whatever course the student adopts at first, it is quite likely that he will eventually find himself anxious to explore some of the theories and laws of the scientist. Even those which prove impractical to him will at least enrich his general knowledge and appreciation of color. If one fails to investigate this scientific material, he is almost certain to deprive him­self of a wealth of adaptable sugges­tions which have been developed during centuries of intelligent and conscientious research on the part of many earnest workers approaching the subject of color from every pos­sible point of view. The longer one studies, the more he comes to real­ize that some theories or laws, which on first comparison seem poles apart, actually are, at least when it comes to their practical application, parallel rather than di­vergent. The student who studies them thoroughly will find that they lead in the same direction —forward.

Are You Ready To Move Onto The Next Lesson? Click Here….