A Color Notation/Chapter 4
Pure color is seen in the spectrum of sunlight.
(87) The strongest sensation of color is gained in a darkened room, with a prism used to split a beam of sunlight into its various An image should appear at this position in the text. wave lengths. Through a narrow slit there enters a straight pencil of light which we are accustomed to think of as white, although it is a bundle of variously colored rays (or waves of ether) whose union and balance is so perfect that no single ray predominates.
(88) Cover the narrow slit, and we are plunged in darkness. Admit the beam, and the eye feels a powerful contrast between the spot of light on the floor and its surrounding darkness. Place a triangular glass prism near the slit to intercept the beam of white light, and suddenly there appears on the opposite wall a band of brilliant colors. This delightful experiment rivets the eye by the beauty and purity of its hues. All other colors seem weak by comparison. Their weakness is due to impurity, for all pigments and dyes reflect portions of hues other than their dominant one, which tend to “gray” and diminish their chroma.
(89) But prismatic color is pure, or very nearly so, because the shape of the glass refracts each hue, and separates it by the length of its ether wave. ‘These waves have been measured, and science can name each hue by its wave length. ‘Thus a certain red is known as M. 6867, and a certain green sensation is M. 5269.[1] Without attempting any scientific analysis of color, let it be said that Sir Isaac Newton made his series of experiments in 1687, and was privileged to name this color sequence by seven steps which he called red, orange, yellow, green, blue, violet, and indigo. Later a scientist named Fraunhofer discovered fine black lines crossing the solar spectrum, and marked them with letters of the alphabet from a to h. These with the wave length serve to locate every hue and define every step in the sequence. Since Newton’s time it has been proved that only three of the spectral hues are primary; viz., a red, a green, and a violet-blue, while their mixture produces all other gradations. By receiving the spectrum on an opaque screen with fine slits that fit the red and green waves, so that they alone pass through, these two primary hues can be received on mirrors inclined at such an angle as to unite on another screen, where, instead of red or green, the eye sees only yellow.[2]
(90) A similar arrangement of slits and mirrors for the green and violet-blue proves that they unite to make blue, while a third experiment shows that the red and violet-blue can unite to make purple. So yellow, blue-green, and purple are called secondary hues because they result from the mixture of the three primaries, red, green, and violet-blue.
In comparing these two color lists, we see that the “indigo” and “orange” of Sir Isaac Newton have been discarded. Both are indefinite, and refer to variable products of the vegetable kingdom. Violet is also borrowed from the same kingdom; and, in order to describe a violet, we say it is a purple violet or blue violet, as the case may be, Just as we describe an orange as a red orange or a yellow orange. ‘Their color difference is not expressed by the terms “orange” or “violet,” but by the words “red,” “vellow,”’ “blue,” or “purple,” all of which are true color names and arouse an unmixed color image.
(91) In the nursery a child learns to use the simple color names red, yellow, green, blue, and purple. When familiarity with the color sphere makes him relate them to each other and place them between black and white by their degree of light and strength, there will be no occasion to revert to vegetables, animals, minerals, or the ever-varying hues of sea and sky to express his color sensations.
(92) Another experiment accentuates the difference between spectral and pigment color. When the spectrum is spread on the screen by the use of a prism, and a second prism is placed inverted beyond the first, it regathers the dispersed rays back into their original beam, making a white spot on the floor. This proves that all the colored rays of light combine to balance each other in whiteness. But if pigments which are the closest possible imitation of these hues are united on a painter’s palette, either by the brush or the knife, they make gray, and not white.
(93) This is another illustration of the behavior of pigments, for, instead of uniting to form white, they form gray, which is a darkened or impure form of white; and, lest this should be attributed to a chemical reaction between the various matiers that serve as pigments, the experiment can be carried out without allowing one pigment to touch another by using Maxwell discs, as will be shown in the next chapter.
(94) Before leaving these prismatic colors, let us study them in
the light of what has already been learned of color dimensions.
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Fig. 15
Not only do they present different values,
but also different chromas. Their values
range from darkness at each end, where red
and purple become visible, to a brightness in
the greenish yellow, which is almost white.
So on the color tree described in Chapter II.,
paragraph 34, yellow has the highest branch,
green is lower, red is below the middle, with
blue and purple lower down, near black.
(95) Then in chroma they range from the powerful stimulation of the red to the soothing purple, with green occupying an intermediate step. This is also given on the color tree by the length of its branches.
(96) In Fig. 15 the vertical curve describes the values of the spectrum as they grade from red through yellow, green, blue, and purple. The horizontal curve describes the chromas of the spec- trum in the same sequence; while the third curve leaning outward is obtained by uniting the first two by two planes at right angles to one another, and sums up the three qualities by a single descriptive line. Now the red and purple ends are far apart, and science forbids their junction because of their great difference in wave length. But the mind is prone to unite them in order to produce the red-purples which we see in clouds at sunset, in flowers and grapes and the amethyst. Indeed, it has been done unhesitatingly in most color schemes in order to supply the opposite of green.
(97) This gives a slanting circuit joining all the branch ends of the color tree, and has been likened to the rings of Saturn in Chapter I., paragraph 17.
A prismatic color sphere.
(98) With a little effort of the imagination we can picture a prismatic color sphere, using only the colors of light. In a cylindrical chamber is hung a diaphanous ball similar to a huge soap bubble, which can display color on its surface without obscuring its interior. ‘Then, at the proper points of the surrounding wall, three pure beams of colored light are admitted,—one red, another green, and the third violet-blue.
(99) They fall at proper levels on three sides of the sphere, while their intermediate gradations encircle the sphere with a complete spectrum plus the needed purple. As they penetrate the sphere, they unite to balance each other in neutrality. Pure whiteness is at the top, and, by some imaginary means their light gradually diminishes until they disappear in darkness below.
(100) This ideal color system is impossible in the present state of our knowledge and implements. Even were it possible, its immaterial hues could not serve to dye materials or paint pictures. Pigments are, and will in all probability continue to be, the practical agents of coloristic productions, however reluctant the scientist may be to accept them as the basis of a color system. It is true that they are chemically impure and imperfectly represent the colors of light. Some of them fade rapidly and undergo chemical change, as in the notable case of a green pigment tested by this measured system, which in a few weeks lost four steps of chroma, gained two steps of value, and swung into a bluer hue.
(101) But the color sphere to be next described is worked out with a few reliable pigments, mostly natural earths, whose fading is a matter of years and so slight as to be almost imperceptible. Besides, its principal hues are preserved in safe keeping by imperishable enamels, which can be used to correct any tendency of the pigments to distort the measured intervals of the color sphere.
This meets the most serious objection to a pigment system. Without it a child has nothing tangible which he can keep in constant view to imitate and memorize. With it he builds up a mental image of measured relations that describe every color in nature, including the fleeting hues of the rainbow, although they appear but for a moment at rare intervals. Finally, it furnishes a simple notation which records every color sensation by letters and numerals. With the enlargement of his mental power he will unite these in a comprehensive grasp of the larger relations of color.
Children’s Color Studies.
These reproductions of children’s work are given as proof that color charm and good taste may be cultivated from the start.
Five Middle Hues are first taught by the use of special crayons, and later with water colors. They represent the equator of the color sphere (see Plate I.),—a circle midway between the extremes of color-light and color-strength,—and are known as Middle Red, Middle Yellow, Middle Green, Middle Blue, and Middle Purple.
These are starting-points for training the eye to measure regular scales of Value and Chroma.[3] Only with such a trained judgment is it safe to undertake the use of strong colors.[4]
Beginners should avoid Strong Color. Extreme red, yellow, and blue are discordant. (They “shriek” and “swear.” Mark Twain calls Roxana’s gown “a volcanic eruption of infernal splendors.”) Yet there are some who claim that the child craves them, and must have them to produce a thrill. So also does he crave candies, matches, and the carving-knife. He covets the trumpet, fire-gong, and bass-drum for their “ thrill’; but who would think them necessary to the musical training of the ear? Like the blazing bill-board and the circus wagon, they may be suffered out-of-doors; but such boisterous sounds and color sprees are unfit for the school-room.
Quiet Color is the Mark of Good Taste. Refinement in dress and the furnishings of the home is attractive, but we shrink from those who are “loud” in their speech or their clothing. If we wish our children to become well-bred, is it logical to begin by encouraging barbarous tastes? ‘Their young minds are very open to suggestion. They quickly adopt our standards, and the blame must fall upon us if they acquire crude color habits. Yellow journalism and rag-time tunes will not help their taste in speech or song, nor will violent hues improve their taste in matters of color.
Balance of Color 1s to be sought. Artists and decorators are well aware of a fact that slowly dawns upon the student; namely, that color harmony is due to the preservation of a subtle balance and impossible by the use of extremes. This balance of color resides more within the spherical surface of this system than in the excessive chromas which project beyond. It is futile to encourage children in efforts to rival the poppy or buttercup, even with the strongest pigments obtainable. Their sunlit points give pleasure because they are surrounded and balanced by blue ether and wide green fields. Were these conditions reversed, so that the flowers appeared as little spots of blue or green in great fields of blazing red, orange, and yellow, our pained eyes would be shut in disgust.
The painter knows that pigments cannot rival the brilliancy of the buttercup and poppy, enhanced by their surroundings. What is more, he does not care to attempt it. Nor does the musician wish to imitate the screech of a siren or the explosion of a gun. These are not subjects for art. Harmonious sounds are the study of the musician, and tuned colors are the materials of the colorist. Corot in landscape, and Titian, Velasquez, and Whistler in figure painting, show us that Nature’s richest effects and most beautiful color are enveloped in an atmosphere of gray.
Beauty of Color lies in Tempered Relations. Music rarely touches the extreme range of sound, and harmonious color rarely uses the extremes of color-light or color-strength. Regular scales in the middle register are first given to train the ear, and so should the eye be first familiarized with medium degrees of color.
This system provides measured scales, established by special instruments, and is able to select the middle points of red, yellow, green, blue, and purple as a basis for comparing and relating all colors. ‘These five middle colors form a Chromatic Tuning Fork. (See page 70.) It is far better that children should first become familiar with these tuned color intervals which are harmonious in themselves rather than begin by blundering among unrelated degrees of harsh and violent color. Who would think of teaching the musical scale with a piano out of tune?
The Tuning of Color cannot be left to Personal Whim. 'The wide discrepancies of red, yellow, and blue, which have been falsely taught as primary colors, can no more be tuned by a child than the musical novice can tune his instrument. Each of these hues has three variable factors (see page 14, paragraph 14), and scientific tests are necessary to measure and relate their uneven degrees of Hue, Value, and Chroma.
Visual estimates of color, without the help of any standard for comparison, are continually distorted by doubt, guess-work, and the fatigue of the eye. Hardly two persons can agree in the intelligible description of color. Not only do individuals differ, but the same eye will vary in its estimates from day to day. A frequent assumption that all strong pigments are equal in chroma, is far from the truth, and involves beginners in many mishaps. ‘Thus the strongest blue-green, chromium sesquioxide, is but half the chroma of its red complement, the sulphuret of mercury. Yet ignorance is constantly leading to their unbalanced use. Indeed, some are still unaware that they are the complements of each other.[5]
It is evident that the fundamental scales of Hue, Value, and Chroma must be established by scientific measures, not by personal bias. ‘This system is unique in the possession of such scales, made possible by the devising of special instruments for the measurement of color, and can therefore be trusted as a permanent basis for training the color sense.
The examples in Plates II. and III. show how successfully the tuned crayons, cards, and water colors of this system lead a child to fine appreciations of color harmony.
PLATE II.
Color Studies with TUNED CRAYONS in the Lower Grades.
Children have made every example on this plate, with no other material than the five crayons of middle hue, tempered with gray and black. A Color Sphere is always kept in the room for reference, and five color balls to match the five middle hues are placed in the hands of the youngest pupils. Starting with these middle points in the scales of Value and Chroma, they learn to estimate rightly all lighter and darker values, all weaker and stronger chromas, and gradually build up a disciplined judgment of color.
Each study can be made the basis of many variations by a simple change of one color element, as suggested in the text.
1. Butterfly. Yellow and black crayon. Vary by using any single crayon with black.
2. Dish. Red crayon, blue and green crayons for back and foreground. Vary by using the two opposites of any color chosen for the dish and omitting the two neighbor- ing colors. See No. 4.
3. Hiawatha’s canoe. Yellow crayon, with rim and name in green. Vary color of canoe, keeping the rim a neigh- boring color. ‘See No. 4.
4. Color-circle. Gray crayon for centre, and five crayons spaced equidistant. This gives the invariable order, red, yellow, green, blue, purple. Never use all five in a single design. Either use a color and its two neighbors or a color and its two opposites. By mingling touches of any two neighbors, the intermediates are made and named yellow-red (orange), green-yellow, blue-green, purple-blue (violet), and red- purple. Abbreviated, the circle reads R, YR, Y, GY, G, BG, B, PB, P, RP.
5. Rosette. Red cross in centre, green leaves: blue field, black outline. Vary as in No. 2.
6. Rosette. Green centre and edge of leaves, purple field and black accents. Vary color of centre, keeping field two colors distant.
7. Plaid. Use any three crayons with black. Vary the trio.
8. Folding screen. Yellow field (lightly applied), green and black edge. Make lighter and darker values of each color, and arrange in scales graded from black to white.
9. Rug. Light red field with solid red centre, border pattern and edges of gray. This is called self-color. Change to each of the crayons.
10. Rug. Light yellow field and solid centre, with purple and black in border design. Vary by change of ground, keeping design two colors distant and darkened with black.
11. Lattice. Yellow with black: alternate green and blue lozenges. Vary by keeping the lozenges of two neighboring colors, but one color removed from that of the lattice.
For principles involved in these color groups, see Chapter II.
PLATE III.
Color Studies with TUNED WATER COLORS in the Upper Grades.
Previous work with measured scales, made by the tuned crayons and tested by reference to the color sphere, have so trained the color judgment that children may now be trusted with more flexible material. They have memorized the equable degrees of color on the equator of the sphere, and found how lighter colors may balance darker colors, how small areas of stronger chroma may be balanced by larger masses of weaker chroma, and in general gained a disciplined color sense. Definite impressions and clear thinking have taken the place of guess-work and blundering.
Thus, before reaching the secondary school, they are put in possession of the color faculty by a system and notation similar to that which was devised centuries ago for the musical sense. No system, however logical, will produce the artist, but every artist needs some systematic training at the outset, and this simple method by measured scales is believed to be the best yet devised.
Each example on this plate may be made the basis of many variants, by small changes in the color steps, as suggested in the text, and further elaborated in Chapter VI. Indeed, the studies reproduced on Plates II. and III. are but a handful among hundreds of pleasing results produced in a single school.[6]
1. Pattern. Purple and green: the two united and thinned with water will give the ground. Vary with any other color pair.
2. Pattern. Figure in middle red, with darker blue-green accent. Ground of middle yellow, grayed with slight addition of the red and green. Vary with purple in place of blue-green.
3. Japanese teapot. Middle red, with background of lighter yellow and foreground of grayed middle yellow.
4, Variant on No. 3. Middle yellow, with slight addition of green. Foreground the same, with more red, and background of middle gray.
5. Group. Background of yellow-red, lighter vase in yellow-green, and darker vase of green, with slight addition of black. Vary by inversion of the colors in ground and darker vase.
6. Wall decoration. Frieze pattern made of cat-tails and leaves,—the leaves of blue-green with black, tails of yellow-red with black, and ground of the two colors united and thinned with water. Wall of blue-green, slightly grayed by additions of the two colors in the frieze. Dado could be a match of the cat-tails slightly grayer. See Fig. 23, page 82.
7. Group. Foreground in purple-blue, grayed with black. Vase of purple-red, and background in lighter yellow- red, grayed.
For analysis of the groups and means of recording them, see Chapter III.
- ↑ See Micron in Glossary.
- ↑ The fact that the spectral union of red and green makes yellow is a matter of surprise to practical workers in color who are familiar with the action of pigments, but unfamiliar with spectrum analysis. Yellow seems to them a primary and indispensable color, because it cannot be made by the union of red and green pigments. Another surprise is awaiting them when they hear that the yellow and blue of the spectrum make white, for all their experience with paints goes to prove that yellow and blue unite to form green. Attention is called to this difference between the mixture of colored light and of colored pigments, not with the idea of explaining it here, but to emphasize their difference; for in the next chapter we shall describe the practical making of a color sphere with pigments, which would be quite impractical, could we have only the colors of the spectrum to work with. See Appendix to preceding chapter.
- ↑ See Century Dictionary for definition of chroma. Under the word ‘‘color” will be found definitions of Primary, Complementary, Constants (chroma, luminosity, and hue), and the Young-Helmholtz theory of color-sensation.
- ↑ It must not be assumed because so much stress is laid upon quiet and harmonious color that this system excludes the more powerful degrees. To do so would forfeit its claim to completeness. A Color Atlas displays all known degrees of pigment color arranged in measured scales of Hue, Value, and Chroma.
- ↑ See Appendix to Chapter III.
- ↑ The Pope School, Somerville, Mass.
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Copyright 1907 by A.H. Munsell.
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Copyright 1907 by A.H. Munsell.