Elementary Color

by Milton Bradley

In combining red and blue disks to make a violet the result is more satisfactory, while if we attempt to produce a green by combining the yellow and blue disks the result will be surprising, but probably not convincing, because the statement that yellow and blue make green has been so persistently reiterated as a fundamental axiom that people who have given the subject but little attention will feel that to doubt it is rank heresy. In a text book treating of color is found the following passage: "Green substances reflect the green, i.e., the blue and yellow rays of the sunlight and absorb all the others." It is a fact, however, that in the mixture of blue and yellow light there is little or no trace of green, as a single experiment with a color top or color wheel will readily demonstrate.

In response to this convincing experiment a colorist of the "old school," (and there are few others) will doubtless say, "Such an assertion seems to be true when applied to these rotating disks, but we see no practical value in experiments of this kind, because in the use of color we must depend on pigmentary combinations, and in pigments yellow and blue do make green." The author of a statement of this kind is always honest in making it, and yet it is absolutely untrue, because as has already been shown, the green resulting from the mixture of yellow and blue can not be placed even approximately in the same class as the yellow and blue of which it is composed.

In accepting the disk combinations of standard pigmentary colors we are assuming a system of color investigation based on the combination of colored light rather than the mixture of pigments, and to an artist who has given the subject little thought this seems quite radical, not to say startling. But, logically, why is it not the most natural as well as the correct basis for this work?

Art in color must be based on the imitation of natural color effects. We must first learn to see color correctly and to know what we see, and after that it is a very simple matter to learn which pigments to combine for producing any desired result which is already clearly defined in the mind. In fact the best selection of pigments must often be based on their chemical and mechanical qualities as much as on their peculiar hues.

All color impressions of material substances are produced by colored light reflected from a material surface to the retina of the eye, through which by some unknown means it is conveyed to the brain. When the white sunlight falls on a material substance a portion of the rays are absorbed and others are reflected to the eye, thereby conveying impressions of color. If on a surface of yellow material we throw a strong orange light through a colored glass, some of the orange rays from the glass will mingle with the yellow rays and the two are reflected to the eye, thereby producing an orange yellow or yellow orange effect where before it was yellow. So in a summer evening landscape when there is a so-called red sunset, everything is illuminated by an orange light and each color in the landscape is affected by the orange rays which mingle with the rays of the local color and are reflected to the eyes of the observer, producing the effect of local colors mixed with orange.

In a room where the windows open on to a green lawn with many trees in close proximity to the house, nearly all the light is reflected from green surfaces, and hence is green light. In such a case a correct painting of objects in that room would have a general green effect.

The afternoon light in a room on the west side of a city street may be nearly all red light, reflected from an opposite red brick wall, and such a room would be ill-adapted to showing fine dress goods, because the hues of the more delicate colors would be entirely changed, and hence would give a false impression as to the relations of the several colors in combination as seen in white or clear daylight. If a piece of light blue silk is illuminated by sunlight passing through a bit of yellow glass, no trace of green effect will be produced, but a gray either slightly yellow or blue, according to the relative strength of the colors in the glass and the silk. This same effect would be secured if the yellow light of the setting sun illuminated the same material, but under such conditions everything else would be similarly affected so that the effect would not be so apparent.

The idea that all color is derived from the three primaries, red, yellow and blue, is so generally believed that our best writers among artists, colorists and educators have repeated it for many years. George Barnard, an English artist, in a very valuable book on water color painting, speaking of the colors of the spectrum which may be re-combined to form white light, says that if the yellow and blue rays are combined they produce green.

Chevreul also states in his invaluable book on color contrasts that yellow and blue threads woven into a texture, side by side, produce green. This statement is the more remarkable because the writer was a very careful investigator and is but another evidence of the strong hold which the Newton and Brewster theory has had on the public mind for so many years.

The story is told of an artist who wished to introduce into a composition of still life a blue vase with a bit of yellow lace thrown over a portion of it, and having been educated to believe that yellow and blue made green, gave a green effect to the portion of the vase covered by the lace. Had he known that blue and yellow light combined make gray instead of green he would have avoided the error.