Part 5

As all color is contained in white light, if we take from white light any given color, the color remaining is the complementary. If a small disk of standard red paper is placed on a white wall and the eyes fixed intently on it for a few seconds, and then the eyes slightly moved back and forth, a ring of a bluish green tint will be seen surrounding the red paper, or if the eyes are fixed intently on the disk for a short time and the paper suddenly removed, a disk of the same blue green tint will be seen in place of the red disk. This is called the accidental color and is supposed to be identical with the complementary color, although the image is too faint to give any very exact effect, but it is sufficient to furnish a clue to the complementary, and we may infer that a color between green and blue is that which is required. Now if we can determine in what proportions red, blue and green must be united to produce white light we may solve the problem. This is not possible in the use of any pigmentary colors, because of the impurity of all pigments as compared with spectrum colors. Although the mixture of colored light reflected from the disks, which are made of pigmentary colors, gives much purer color than the actual mechanical mixture of the two pigments, still, because it is a reflection of pigmentary colors, it is far lower in tone than the corresponding mixture of spectrum colors. Therefore it can not be a pure white, but may be white in shade or a neutral gray, which, as already shown, can be produced by the combination of a white and a black disk.

Therefore if red, blue and green disks of medium size are joined on the wheel and in front of them small white and black disks are combined, we have a means for solving this problem. If these various disks can be so adjusted that when rotated the effect of the three colored disks is a neutral gray, (or white under a low degree of illumination) exactly matching a gray that may be obtained by adjusting the small black and white disks, then one step in the solution is taken, as shown in Fig. 12.

With such an arrangement a very close match is produced, when the combined disks show the proportions to be R. 41-1/2, B. 22-1/2, G. 36 for the larger disks, and for the small disks W. 15, and N. 85. Now if blue and green are combined in the same proportions, as indicated above and in quantities sufficient when added together to fill the entire circle of 100 parts, blue will contain 38.3 parts and green, 61.7 parts, as shown in Fig. 13, and the disks when rotated will give the color which is the complementary of red: namely, a blue green.

In the same way the complementary of each of the other standard colors, and in fact of any color, may be obtained.

The complementary of orange is another color between the green and blue, but more largely blue. The complementary of green is a violet red, and of violet a color between yellow and green, while yellow and blue are very nearly complementary to each other.

These figures furnish the results in a very well-lighted room, with a perfectly white interior. It is a well-established fact that this experiment is somewhat affected by the degrees of illumination, and also that colored light from the walls and ceiling of a room must of necessity have its effect, but all these matters are so insignificant as to be of no material consequence in the æsthetic study of the subject, and they can be very nearly eliminated when necessary by a careful selection of conditions. Whenever accurate experiments in pigmentary color comparisons are to be made, either by the use of rotating disks or otherwise, it is desirable to have a very well-lighted room, with a northern exposure and to select a morning or noonday light from a slightly overcast sky. These conditions obviate the unpleasant effect of direct sunlight in the room and also the very slightly blue effect of the clear sky. These precautions are unnecessary in experiments relating to the ordinary æsthetic consideration of color combinations, but even in such work it is important to exclude all light reflected from neighboring trees or colored buildings. Also the interior of the room should be as free from color as possible; a clean white surface is especially desirable.

A Chart of Complementary Colors, shown in Fig. 14, has been found very valuable in fixing in the minds of teacher and pupils the complementaries of the six standards. In this chart, which is about eighteen inches in diameter, the circles at the ends of the six diameters are colored papers selected from the Bradley coated papers, as approximating the true complementaries. In the majority of cases they are not far from correct, but are least satisfactory in the blue and yellow. Theoretically the complementary of the ideal standard blue is a slightly orange yellow, and of the standard yellow a slightly violet blue. But there is as yet no blue pigment in the market suitable for commercial use which is free from a slightly violet effect. Therefore the standard blue paper is practically as good a complementary for the standard yellow as the violet blue paper. But notwithstanding these slight imperfections which are at present unavoidable, the chart is a valuable aid in fixing in the mind the positions of the complementary pairs in the spectrum circuit.

Each of the foregoing experiments furnishes an interesting class exercise, and may be very closely repeated by the pupils with their tops. Also the computation of the proportion of green and blue when raised to the full circle may form a practical problem in proportion for pupils of the higher grades. Taken together, these experiments prove that the complementaries of the old primaries are not found in the secondaries.

The last claim of the Brewster theory is that the secondaries by combination form three lines of colors peculiar to themselves, called citrines, russets and olives. It is asserted that the mixture of orange and green makes citrine; orange and violet russet; green and violet olive. Although these names may be very convenient terms to express three general classes of colors, they must of necessity be too general and indefinite to be of value for accurate expression of color effects, and are in fact so vague that hardly two persons can be found in a large company who will agree as to the best expression of either of them. The following are formulas for a number of colors in each class, as made from analyses of colors coming under these names. It is an interesting exercise to produce some of these colors by means of the rotating color disks and test the opinions of the different members of a company as to which best represents to each one of them a tertiary color, as citrine, for example. For this purpose three different formulas may be shown at the same time, with three sizes of disks.

Citrines.

O. 7. Y. 13. W. 3-1/2. N. 76-1/2. Y. 15. W. 4. N. 81. Y. 13. W. 5. N. 76. G. 6. O. 6. Y. 20. W. 4. N. 70. O. 3. Y. 6. W. 8. N. 83.

Russets.

R. 37. O. 8. W. 8. N. 47. R. 79. W. 10-1/2. N. 10-1/2. R. 33. O. 20. W. 6. N. 41. R. 36. O. 4. W. 9. N. 51. R. 47. O. 7. W. 8. N. 38.

Olives.

G. 19. B. 11-1/2. W. 10-1/2. N. 59. G. 13. B. 6. W. 12. N. 69. G. 14. B. 12. W. 8. N. 66. G. 10-1/2. B. 15. W. 8. N. 66-1/2. G. 12-1/2. B. 5-1/2. W. 4. N. 78.

The term citrine theoretically covers all possible combinations of orange and green, but as generally understood those colors which are so near the orange or the green as to very decidedly approach either the one or the other are not included, and, as shown in the above analyses, a citrine is a very broken color ranging from an orange yellow through yellow to a green yellow.

Although the russets would theoretically range from violet to orange, yet the general conception of russet will hardly accept a violet red, but will cover only the red and orange reds as above indicated, while olives are confined to blue greens and green blues.

These tests are based on combinations of the Bradley standard orange, green and violet pigments, and therefore are far stronger in color than those colors usually termed citrine, russet and olive, made by mixing the pigmentary secondaries. For example, if a yellow and blue pigment are mixed to form a green, and red and yellow pigments to make an orange, and then this green and orange are mixed to produce a citrine, the result will be very much darker and more broken than the mixture of the purer orange and green colors used as standards.

Restricted to these limits these names may become very useful terms for general color expressions, as covering three different classes of broken colors. If any one believes that these color formulas do not correctly represent the three classes of colors indicated, a series of experiments with even the small color top will prove very convincing.

When the subject of standards as a means for identifying colors is mentioned artists frequently express the feeling that the names of pigments are good enough for them, such as Ultramarine Blue, Prussian Blue, Vermilions, the Siennas, Indian Red, etc. The following are the analyses of several samples of Vermilion, Burnt Sienna, Raw Sienna, and Indian Red of the best tube oil colors in the market:--

Vermilion.

R. 80. O. 14. W. 6. R. 87. O. 8. W. 5. R. 50. O. 24. W. 26.

Burnt Sienna.

R. 1-1/4. O. 6. W. 3. N. 89-1/2. R. 22-1/2. O. 11-1/2. W. 2. N. 64. R. 25. O. 12-1/2. W. 5-1/2. N. 57.

Raw Sienna.

O. 18-1/2. Y. 6-1/2. N. 75. O. 17. Y. 14. W. 1. N. 68. O. 8-1/2. Y. 3-1/2. W. 2. N. 86.

Indian Red.

R. 11-1/2. O. 7. W. 4. N. 77-1/2. R. 13-1/2. O. 13-1/2. W. 2-1/2. N. 70-1/2.

A careful examination of these formulas and a reproduction and comparison of the colors on the color top will convince any one that in no case does the commercial name determine the color with a degree of accuracy sufficient for any valuable nomenclature.

Classification of Harmonies.

The theory of the harmonies of colors is a subject which awaits very careful investigation and a general discussion by artists and expert colorists. Such investigations must include many experiments based on common standards and uniform methods of measurements and records.

Harmonies naturally seem to fall into a few general classes which are convenient for comparison and discussion as well as for elementary instruction, but no one person can set himself or herself up to decide which are the _best_ harmonies. The practices and recommendations of noted artists who have appeared to be gifted with intuitive perceptions regarding color combinations have frequently included those for which there seemed to be no recognized authority, and yet their beauty could not be questioned. As the rules of grammar are but the correlation of the practices of the best scholars, so the rules governing color combinations must be the summary of the practices and recommendations of the best artists, if they are to be generally accepted as final, and hence we must patiently await the growth of similarly established laws by the comparison of the opinions of critics of acknowledged ability in various departments of the world of art. This has not been possible in the past and can never occur until there is a language of color through which color facts can be somewhat accurately expressed in verbal and written language, and this language cannot exist until there is an accepted alphabet of color on which it can be based. This alphabet is now in part furnished by the spectrum standards and completed by the pigmentary standards and the rotating disks made like them. Together they form the basis for a nomenclature by the use of which the questions involved in harmonies can be discussed and the results expressed in written language.

In the investigation of any subject with a view to elementary instruction, classification is an important factor, but one which heretofore has been almost ignored as regards color education. Consequently at present the more definite division of harmonies into classes is very much a matter of personal opinion, but Mr. Henry T. Bailey, State Supervisor of Drawing in Massachusetts, has suggested a very useful classification in which he arranges all harmonies under these five heads: Contrasted, Dominant, Complementary, Analogous and Perfected.

_Contrasted._--The contrasted harmonies are those in which color is contrasted with non-color, or more accurately in which an active color, that is a tone from the spectrum circuit, is contrasted with a passive color, white, black, gray or silver and gold; for example, a blue green tint with white, or green blue with warm gray No. 1.

_Dominant._--By dominant harmonies we mean those in which are combined different tones from one color scale. For example, red tint No. 1, and red shade No. 1, or a green blue tint, green blue, and a green blue shade. A dominant harmony composed of grays, or white, gray and black, is sometimes called a neutral harmony.

_Complementary._--This term refers to those harmonies in which are combined opposite or complementary colors in the spectrum circuit. The best of them show not only opposition in color but also opposition in tone. Thus, tints of one color with shades of its complementary produce a more pleasing effect than do complementaries of equal value. The best complementary harmonies contain one or more passive colors.

_Analogous._--This name is applied to those harmonies in which are combined tones from scales of neighboring colors in the spectrum circuit.

For example, in a composition of colors from that part of the spectrum containing yellow, green yellow and yellow green the following simple combination may be made: Yellow tint No. 1, green yellow and yellow green shade No. 2.

_Perfected._--By perfected harmonies we mean those in which the general effect of one analogous harmony is complementary to that of another.

The above classification of harmonies is very valuable for fixing in the mind the various effects of color combinations, and yet they may seem to somewhat merge into each other in their application, until the underlying principles which govern them are understood. It is unwise to suppose that because the above classification of harmonies is based on the science of color we can infer that it furnishes definite rules for producing best effects.

The Work of Chevreul Reviewed.

The good or bad effect of two or more colors in combination in decorative designs or fine art depends very largely upon phenomena which are elaborately explained in a book entitled "The principles of Harmony and Contrasts of Colours" by M. Chevreul.[A] The first edition of this book was prepared in 1835 and published in 1838. The author had at that time been employed for a number of years as superintendent of the manufactory of Gobelin Tapestries in Paris under the control of the French government.

[A] The Principles of Harmony and Contrasts of Colours and their Application to the Arts. By M. E. Chevreul. Translated from the French by Charles Martel. Third Edition. London. George Bell and Sons. 1890.

In this book are described in detail the results of a great number of experiments which were instigated by complaints regarding certain colors produced in the dyeing department of the manufactory, and which afford the most elaborate exposition of the subject ever published.

One of the first things which led Chevreul to make his investigation was the complaint that certain black yarns used as shades in blue draperies were not a full black but more or less gray.

The author says in his preface, "The work I now publish is the result of my researches on Simultaneous Contrasts of Colours; researches which have been greatly extended since the lectures I gave on this subject at the institute on the 7th April, 1828. In reflecting on the relations these facts have together, in seeking the principle of which they are the consequence, I have been led to the discovery of the one which I have named the _Law of Simultaneous Contrast of Colours_."

The closing sentence of the preface to the first edition and dated 1835 is as follows:--

"I beg the reader never to forget when it is asserted of the phenomena of simultaneous contrast, _that one colour placed beside another receives such a modification from it_, that this manner of speaking does not mean that two colours, or rather the two material objects that present them to us, have a mutual action, either physical or chemical; it is really only applied to the modification that takes place before us when we perceive the simultaneous impression of these two colours."

It was not till three years later that a publisher could be found for this book, which is still a standard.

The English translation comprises over five hundred closely printed pages with many engraved and colored plates, and yet, it has been of comparatively little value in _popular instruction_ because of the lack of a generally accepted color nomenclature or list of well defined color terms, by which the readers might have understood and repeated for themselves the experiments described.

Unfortunately Chevreul was fully impressed with the Newton-Brewster idea of three primaries, red, yellow and blue, and therefore some of his deductions from his experiments seem to have been more or less influenced by the attempt to make them harmonize with this theory, and yet the subject which he has treated so exhaustively and intelligently is one of the most important in the æsthetic study and use of colors. In all expressions of colors in combination with each other, whether in nature, fine arts or the decorative and industrial arts, every color is affected by its surrounding colors, a fact which is exhaustively treated in this book.

While with our present knowledge of the subject it does not seem that the material use of color can be reduced to an exact science, this should not prevent us from accepting all the natural and scientific aids which have been or may be discovered toward this desirable result. Because of this lack of scientific knowledge in Chevreul's time much of the worth of his experiments is lost to us, yet there is very much of value in his work, suggesting as it does experiments which may be tried with present standards and modern methods.

If the use of Maxwell disks had been known to Chevreul his deductions from his experiments would have been quite different in their details. For example, in accepting the proposition that there are three primaries, red, yellow and blue, which may be combined in pairs to make the secondaries, orange, green and violet, he states that owing to the impurities of the pigments the secondaries are not as pure as the primaries. Consequently he believes that this may account for many of the shortcomings which he was too observing to overlook; but notwithstanding such an error in theory this wonderful investigator made many practical experiments and established very valuable facts regarding color contrasts.

The term Simultaneous Contrast seems rather restricted for a title covering such a range of effects, and the author subdivides the subject into simultaneous contrasts, successive contrasts and mixed contrasts, which he defines as follows:--

Simultaneous Contrast.

"In the Simultaneous Contrast of Colors is included all the phenomena of modification which differently colored objects appear to undergo in their physical composition and in the height of tone of their respective colors, when seen simultaneously."

Successive Contrast.

"The Successive Contrast of Colors includes all the phenomena which are observed when the eyes, having looked at one or more colored objects for a certain length of time, perceive, upon turning them away, images of these objects having a color complementary to that which belongs to each of them."

Mixed Contrast.

"The distinction of Simultaneous and Successive Contrast renders it easy to comprehend a phenomenon which we may call the mixed contrast; because it results from the fact that the eye, having seen for a time a certain color, acquires an aptitude to see for another period the complementary of that color, and also a new color, presented to it by an exterior object; the sensation then perceived is that which results from this new color and the complementary of the first." These last two effects may be shown very clearly in simple experiments.

There are various phenomena which may be classed as successive contrasts sometimes called "after images." The phenomena which Chevreul groups under the term "Simultaneous Contrast of Colors" belong to a class of physio-psychological effects termed after images, and more definitely to the subdivision called negative images. The positive after images are not important in the consideration of the theories of color and therefore are not described here. The specific effect most directly involved in the subject of harmonies may be observed if the eyes are fixed upon a small disk of red paper on a white wall for a few seconds and then the paper is suddenly removed, as there will appear on the wall in place of the full red disk a faint tint of a blue green. This is called an after image, and is nearly or exactly a tint of the color complementary to red.

For making this experiment mount a circle of red paper, say three inches in diameter on a square white card, four or five inches across, and grasping the card by one corner hold it in front of a white wall or a sheet of white paper pinned on any support. Tell the observer to look intently at the red disk for a half minute, and then without giving any notice suddenly remove it and ask what color is seen in place of it. At the first trial the result may not be entirely successful, because the eyes of the observer may naturally follow the red spot when it is removed instead of remaining fixed in the original position, but a second trial will bring the expected result. To illustrate mixed contrast, fasten on the wall a piece of red tint No. 2 paper four or five inches square. This may be very conveniently done by using a bit of beeswax on each corner of the paper, which will not soil the wall. Then having the three-inch circle of standard red paper mounted on a white card somewhat larger than five inches square hold the card in front of the red tint on the wall and repeat the experiment as before. The effect now should be a three-inch disk of very light gray in the center of the pink square, which is a "mixed contrast" according to Chevreul. The reason is simple. The after-image or successive contrast of light blue-green is projected on the red tint and being complementary the resulting effect is a gray. If the red tint could be exactly graded to the complementary effect in the eye the resulting gray circle would be a true neutral gray. Another illustration of the same physical effect by which the complementary is induced may be shown by substituting for the tint of red a light tint of the blue-green paper retaining the full red disk as before. The same blue-green after image is now projected on to the light blue-green paper and hence a circle of more intense blue-green is produced. Thus it is seen that Chevreul's successive and mixed contrasts are both due to the same physiological effect, the only difference being in the ground on to which the after image is projected.