The Color Wheel and
the Natural Order
of Colors

The acknowledgment of a natural order appeared in Rood's books, published in 1879 and 1881. The color theorist H. Barrett Carpenter in a 1915 book entitled Colour: A manual of Its Theory and Practice [10] says that, whereas "most of the modern writers on the subject have been content to follow Chevreul, and to accept without question the 'yellow, red, and blue' theory, a long series of experiments convinced me that there were flaws in this theory.... An accidental introduction to Rood's theory set me experimenting afresh . . . . The result has been to verify the truth of Rood's conclusions as to the natural order of colours and as to contrasts, while beyond these there has emerged a new principle which appears to be clearly established in Nature, that of 'Discord.'" [11]

Albert Munsell acknowledged the natural order of colors by placing yellow near the top of his color tree and purple-blue near the bottom--white, of course, being at the very top of the tree trunk and black at the very bottom of the trunk.

The term natural order of colors means simply this: in their purest condition, no matter where they are encountered [in jewels, minerals, flowers, feathers, and so forth]--assuming, of course, that they are seen in a good, clear light--some hues are light in value; some are of a medium value; others are of a dark value. This natural scale is one that lends itself to a kind of artistic structural sense and to a modern color grammar or syntax that started to take shape in the art and sensibility of Turner and Constable [thanks, in part, to the eighteenth-century English amateur tradition of watercolor painting], that carried over into French painting [that of Delacroix, Corot, and Manet, in particular] and blossomed forth in Impressionism in the early 1870s and in subsequent movements, virtually to the present day. [12]

Absolutely pure hues are encountered less often in nature than one would expect. When they are found in, for example, certain flowers and insects, in certain tropical fish, in bird plumage, moths and butterflies, in certain jewel stones, in a rainbow or in a spectacular sunset, they do seem to conform to a natural scale of chromatic values. If we follow carefully a great sunset from beginning to end, we may discover a gradual movement of color down the natural order, from golden yellow to orange, to red, to crimson, to a grayed violet-blue, thence to nightfall. In autumn, in trees in certain parts of the country, leaves will run the gamut from a singing yellow, to a kind of orange or salmon, to an assortment of reds, to crimson, and up or down the scales of hue and value from their original green, all the way to a rich purple-brown. Some of these gradations may be found in a single leaf, including the original green.

Another way of describing this stepwise movement up and down both sides of the color wheel--the warm side [the yellows and reds] or the cool blue-green and blue side--would be to say that color manifests itself according to a set of values ranging from light [almost, but not quite, on a par with pure white] to dark [close to the condition of black]. Certain hues, such as violet and ultramarine blue, pertain to what we shall refer to as the dark register, to the bottom sector of the value scale; red and green, for instance, pertain to the middle register; yellow and orange-yellow pertain to the light register, to the upper end of the scale. Yellow assumes the position of the lightest hue, and violet that of the darkest, in their natural order. That pure yellow and pure violet are very close to being what are called complementaries, or natural opposites, is another factor accounted for in the wheel--the spokes running from one side through the center of the wheel to another side indicate these contrasting pairs, based on their afterimages. This circular scale of colors parallels the achromatic scale or value scale that forms the trunk of MunsellÍs color tree. That no hue, in its natural order, touches the extremes of the achromatic scale [the no-color scale] is readily understood; pure yellow cannot be as light in value as pure white, and pure violet cannot be as dark as pure black [technically the absence of all color, despite the fact that some artists and theorists insist on calling black a color]. The color scale, the wheel, exists within this wider range of values, as it does within the far wider range of the electromagnetic spectrum. [13] We must bear in mind that we are dealing here with pigments and the appearance of color in pigments or colorants, not with colored light, luminous color, or prime radiance. [Prime radiance strikes the eye with far greater energy than color given to use from any kind of surface; and, as was mentioned earlier, paint is a surface.] Naturally, a special case must be made for light passing through colored substances.

Our wheel is known as the psychological wheel. It could be said that there is yet another and far more basic type: the rainbow, the original color wheel! We seldom if ever see the full circle, of course. This would be the physical wheel; however, the bands of colors arrange themselves as concentrics. [Schoolchildren are sometimes taught the prismatic spectrum, the colors of the rainbow, by means of a name that sounds as though it might have been that of some bygone cowboy-movie hero, Roy G. Biv--red, orange, yellow, green, blue, indigo, and violet. Is based on the primaries of white light, primal sunlight, and these are usually described as red, green, and blue; but I believe, with Rood, that James Clerk Maxwell [1831-1879], the Scottish physicist, [14] described them more accurately as vermilion [orange-red], emerald-green [a dark bluey green], and ultramarine-blue [violet-blue]. Their complementaries are green-blue or what is sometimes called cyan [minus red]; red-violet or magenta, a reddish purple [minus green]; and yellow [minus blue]. [Someone suggested that we also need a kind of pigment wheel to "correct" certain discrepancies in the psychological wheel, that the psychological wheel is not subtractive enough in the mixing of colors. For example, the psychological complementaries yellow and ultramarine blue--according to Rood--if mixed in equal portions, would produce a diminished green, not a gray, as complementaries should. But if yellow and violet, next door to ultramarine blue, were mixed, they would surely reduce each other to an achromatic gray, because of the extra red semi-chromes in the violet. It is in matters such as this that color can become ridiculously complicated.]

Back to the psychological wheel: Some wheels contain 10 hues [Munsell's], some 12 [Chevreul's], some 22 [Rood's, in an earlier version; made up of 14 colors--Rood's 12 plus 2 more on both sides of red: orange-red or vermilion, and crimson. The colors consist of pigments in common use and are called, in most instances, by names most artists and paint manufacturers have used over the years. Purple-blue [PB] in the Munsell scheme is called ultramarine blue here and by Rood, since this is the name by which one would normally buy it. But consider the word ultramarine [from the Latin words ultra and marine meaning "beyond the sea"--how poetic!]. The dictionary tells us that it is a deep blue pigment consisting, in earlier times, of powdered lapis lazuli, replaced now by a similar pigment or any of various other pigments in the manufacturing of paints. We shall soon discover that Munsell's commendable effort to apply simple, honest names to colors runs head-on into the "romance" of colors. So we have to try to remember what delicious variety of color each of these charming names is attached to: alizarin crimson, flesh ocher, burnt sienna, Persian orange, Prussian blue, cerulean blue, mountain violet, forest green, olive green, Naples yellow, sepia--and the list goes on. Perhaps there is no way, finally, to scrub colors of their associative qualities, even when they are still in the tube; and the reason probably lies in the way memories of sensations, images, and events seem to be stored in the brain thoroughly laden with feelings. [pp. 92-93]