(24) The color sphere (see Fig. 1) is a convenient model to ill.u.s.trate these three qualities,--hue, value, and chroma,--and unite them by measured scales.
(25) The north pole of the color sphere is white, and the south pole black. Value or luminosity of colors ranges between these two extremes.
This is the vertical scale, to be memorized as _V_, the initial for both value and vertical. Vertical movement through color may thus be thought of as a change of value, but not as a change of hue or of chroma. Hues of color are spread around the equator of the sphere. This is a horizontal scale, memorized as _H_, the initial for both hue and horizontal. Horizontal movement around the color solid is thus thought of as a change of hue, but not of value or of chroma. A line inward from the strong surface hues to the neutral gray axis, traces the graying of each color, which is loss of chroma, and conversely a line beginning with neutral gray at the vertical axis, and becoming more and more colored until it pa.s.ses outside the sphere, is a scale of chroma, which is memorized as _C_, the initial both for chroma and centre. Thus the sphere lends its three dimensions to color description, and a color applied anywhere within, without, or on its surface is located and named by its degree of hue, of value, and of chroma.
[Ill.u.s.tration: Fig. 1.]
+HUES first appeal to the child, VALUES next, and CHROMAS last.+
(26) Color education begins with ability to recognize and name certain hues, such as red, yellow, green, blue, and purple (see paragraphs 182 and 183). Nature presents these hues in union with such varieties of value and chroma that, unless there be some standard of comparison, it is impossible for one person to describe them intelligently to another.
(27) The solar spectrum forms a basis for scientific color a.n.a.lysis, taught in technical schools; but it is quite beyond the comprehension of a child. He needs something more tangible and constantly in view to train his color notions. He needs to handle colors, place them side by side for comparison, imitate them with crayons, paints, and colored stuffs, so as to test the growth of perception, and learn by simple yet accurate terms to describe each by its hue, its value, and its chroma.
(28) Pigments, rather than the solar spectrum, are the practical agents of color work. Certain of them, selected and measured by this system (see Chapter V.), will be known as MIDDLE COLORS, because they stand midway in the scales of value and chroma. These middle colors are preserved in imperishable enamels,[9] so that the child may handle and fix them in his memory, and thus gain a permanent basis for comparing all degrees of color. He learns to grade each middle color to its extremes of value and chroma.
[Footnote 9: When recognized for the first time, a middle green, blue, or purple, is accepted by most persons as well within their color habit, but middle red and middle yellow cause somewhat of a shock. "That isn"t red," they say, "it"s terra cotta." "Yellow?" "Oh, no, that"s--well, it"s a very peculiar shade."
Yet these are as surely the middle degrees of red and yellow as are the more familiar degrees of green, blue, and purple. This becomes evident as soon as one accepts physical tests of color in place of personal whim. It also opens the mind to a generally ignored fact, that middle reds and yellows, instead of the screaming red and yellow first given a child, are constantly found in examples of rich and beautiful color, such as Persian rugs, j.a.panese prints, and the masterpieces of painting.]
(29) Experiments with crayons and paints, and efforts to match middle colors, train his color sense to finer perceptions. Having learned to name colors, he compares them with the enamels of middle value, and can describe how light or dark they are. Later he perceives their differences of strength, and, comparing them with the enamels of middle chroma, can describe how weak or strong they are. Thus the full significance of these middle colors as a practical basis for all color estimates becomes apparent; and, when at a more advanced stage he studies the best examples of decorative color, he will again encounter them in the most beautiful products of Oriental art.
+Is it possible to define the endless varieties of color?+
(30) At first glance it would seem almost hopeless to attempt the naming of every kind and degree of color. But, if all these varieties possess the same three qualities, only in different degrees, and if each quality can be measured by a scale, then there is a clue to this labyrinth.
+A COLOR SPHERE and COLOR TREE to unite hue, value, and chroma.+
(31) This clue is found in the union of these three qualities by measured scales in a _color sphere and color tree_.[10] The equator of the sphere[11] may be divided into ten parts, and serve as the scale of hue, marked R, YR, Y, GY, G, BG, B, PB, P, and RP. Its vertical axis may be divided into ten parts to serve as the scale of value, numbered from black (0) to white (10). Any perpendicular to the neutral axis is a scale of chroma. On the plane of the equator this scale is numbered 1, 2, 3, 4, 5, from the centre to the surface.
[Ill.u.s.tration: Fig. 3.]
[Footnote 10: See Color Tree in paragraph 14.]
[Footnote 11: Unaware that the spherical arrangement had been used years before, I devised a double tetrahedron to cla.s.sify colors, while a student of painting in 1879. It now appears that the sphere was common property with psychologists, having been described by Runge in 1810. Earlier still, Lambert had suggested a pyramidal form. Both are based on the erroneous a.s.sumption that red, yellow, and blue are primary sensations, and also fail to place these hues in a just scale of luminosity. My twirling color solid and its completer development in the present model have always made prominent the artistic feeling for color value.
It differs in this and in other ways from previous systems, and is fortunate in possessing new apparatus to measure the degree of hue, value, and chroma.]
(32) This chroma scale may be raised or lowered to any level of value, always remaining perpendicular to the axis, and serving to measure the chroma of every hue at every level of value. The fact that some colors exceed others to such an extent as to carry them out beyond the sphere is proved by measuring instruments, but the fact is a new one to many persons. (Figs. 2 and 3.)
[Ill.u.s.tration: Fig. 2. (See Fig. 20) The Color Tree]
(33) For this reason the COLOR TREE is a completer model than the sphere, although the simplicity of the latter makes it best for a child"s comprehension.
(34) The color tree is made by taking the vertical axis of the sphere, which carries a scale of value, for the trunk. The branches are at right angles to the trunk; and, as in the sphere, they carry the scale of chroma. Colored b.a.l.l.s on the branches tell their Hue. In order to show the MAXIMA of color, each branch is attached to the trunk (or neutral axis) at a level demanded by its value,--the yellow nearest white at the top, then the green, red, blue, and purple branches, approaching black in the order of their lower values. It will be remembered that the chroma of the sphere ceased with 5 at the equator. The color tree prolongs this through 6, 7, 8, and 9. The branch ends carry colored b.a.l.l.s, representing the most powerful red, yellow, green, blue, and purple pigments which we now possess, and could be lengthened, should stronger chromas be discovered.[12]
[Footnote 12: See Plate I.]
(35) Such models set up a permanent image of color relations. Every point is self-described by its place in the united scales of hue, value, and chroma. These scales fix each new perception of color in the child"s mind by its situation in the color solid. The importance of such a definite image can hardly be overestimated, for without it one color sensation tends to efface another. When the child looks at a color, and has no basis of comparison, it soon leaves a vague memory that cannot be described. These models, on the contrary, lead to an intelligent estimate of each color in terms of its hue, its value, and its chroma; while the permanent enamels correct any personal bias by a definite standard.
(36) Thus defined, a color falls into logical relation with all other colors in the system, and is easily memorized, so that its image may be recalled at any distance of time or place by the notation.
(37) These solid models help to memorize and a.s.semble colors and the memory is further strengthened by a simple NOTATION, which records each color so that it cannot be mistaken for any other. By these written scales a child gains an instinctive estimate of relations, so that, when he is delighted with a new color combination, its proportions are noted and understood.
(38) Musical art has long enjoyed the advantages of a definite scale and notation. Should not the art of coloring gain by similar definition? The musical scale is not left to personal whim, nor does it change from day to day; and something as clear and stable would be an advantage in training the color sense.
(39) Perception of color is crude at first. The child sees only the most obvious distinctions, and prefers the strongest stimulation. But perception soon becomes refined by exercise, and, when a child tries to imitate the subtle colors of nature with paints, he begins to realize that the strongest colors are not the most beautiful,--rather the tempered ones, which may be compared to the moderate sounds in music. To describe these tempered colors, he must estimate their hue, value, and chroma, and be able to describe in what degree his copy departs from the natural color. And, with this gain in perception and imitation of natural color, he finds a strong desire to invent combinations to please his fancy. Thus the study divides into three related att.i.tudes, which may be called recognition, imitation, and invention. Recognition of color is fundamental, but it would be tedious to spend a year or two in formal and dry exercises to train recognition of color alone; for each step in recognition of color is best tested by exercise in its imitation and arrangement. When perception becomes keener, emphasis can be placed on imitation of the colors found in art and in nature, resting finally on the selection and grouping of colors for design.[13]
[Footnote 13: See Course of Study, Part II.]
+Every color can be recognized, named, matched, imitated, and written by its HUE, VALUE, and CHROMA.+
(40) The notation used in this system places Hue (expressed by an initial) at the left; Value (expressed by a number) at the right and above a line; and Chroma (also expressed by a number) at the right, below the line. Thus R 5/9 means HUE (red), VALUE (5)/CHROMA (9), and will be found to represent the qualities of the pigment vermilion.[14]
[Footnote 14: See Chapter VI.]
Hue, value, and chroma unite in every color sensation, but the child cannot grasp them all at once. _Hue-difference appeals to him first_, and he gains a permanent idea of five princ.i.p.al hues from the enamels of MIDDLE COLORS, learning to name, match, imitate, and finally write them by their initials: R (red), Y (yellow), G (green), B (blue), and P (purple). Intermediates formed by uniting successive pairs are also written by the joined initials, YR (yellow-red), GY (green-yellow), BG (blue-green), PB (purple-blue), and RP (red-purple).
(41) Ten differences of hue are as many as a child can render at the outset, yet in matching and imitating them he becomes aware of their light and dark quality, and learns to separate it from hue as _value-difference_. Middle colors, as implied by that name, stand midway between white and black,--that is, on the equator of the sphere,--so that a middle red will be written R 5/, suggesting the steps 6, 7, 8, and 9 which are above the equator, while steps 4, 3, 2, and 1 are below.
It is well to show only three values of a color at first; for instance, the middle value contrasted with a light and a dark one. These are written R 3/, R 5/, R 7/. Soon he perceives and can imitate finer differences, and the red scale may be written entire, as R 1/, R 2/, R 3/, R 4/, R 5/, R 6/, R 7/, R 8/, R 9/, with black as 0 and white as 10.
(42) _Chroma-difference is the third_ and most subtle color quality. The child is already unconsciously familiar with the middle chroma of red, having had the enamels of MIDDLE COLOR always in view, and the red enamel is to be contrasted with the strongest and weakest red chromas obtainable. These he writes R /1, R /5, R /9, seeing that this describes the chromas of red, but leaves out its values. R 5/1, R 5/5, R 5/9, is the complete statement, showing that, while both hue and value are unchanged, the chroma pa.s.ses from grayish red to middle red (enamel first learned) and out to the strongest red in the chroma scale obtained by vermilion.
(43) It may be long before he can imitate the intervening steps of chroma, many children finding it difficult to express more than five steps of the chroma scale, although easily making ten steps of value and from twenty to thirty-five steps of hue. This interesting feature is of psychologic value, and has been followed in the color tree and color sphere.
+Does such a scientific scheme leave any outlet for feeling and personal expression of beauty?+
(44) Lest this exact att.i.tude in color study should seem inartistic, compared with the free and almost chaotic methods in use, let it be said that the stage thus far outlined is frankly disciplinary. It is somewhat dry and unattractive, just as the early musical training is fatiguing without inventive exercises. The child should be encouraged at each step to exercise his fancy.
(45) Instead of cramping his outlook upon nature, it widens his grasp of color, and stores the memory with finer differences, supplying more material by which to express his sense of coloristic beauty.
(46) Color harmony, as now treated, is a purely personal affair, difficult to refer to any clear principles or definite laws. The very terms by which it seeks expression are borrowed from music, and suggest vague a.n.a.logies that fail when put to the test. Color needs a new set of expressive terms, appropriate to its qualities, before we can make an a.n.a.lysis as to the harmony or discord of our color sensations.
(47) This need is supplied in the present system by measured CHARTS, and a NOTATION. Their very construction preserves the _balance of colors_, as will be shown in the next chapter, while the chapter on harmony (Chapter VII.) shows how harmonious pairs and triads of color may be found by MASKS with measured intervals. In fact, practice in the use of the charts supplies the imagination with scales and sequences of color quite as definite and quite as easily written as those sound intervals by which the musician conveys to others his sense of harmony. And, although in neither art can training alone make the artist, yet a technical grasp of these formal scales gives acquaintance with the full range of the instrument, and is indispensable to artistic expression.
From these color scales each individual is free to choose combinations in accord with his feeling for color harmony.
Let us make an outline of the course of color study traced in the preceding pages.[15]
[Footnote 15: _See_ Part II., A Color System and Course of Study.]
+PERCEPTION of color.+
(48) _Hue-difference._
Middle hues (5 princ.i.p.als).
Middle hues (5 intermediates).
Middle hues (10 placed in sequence as SCALE of HUE).