The secondaries in the proportions of 8 orange, 13 purple, 11 green—integrally as 32.
The tertiaries, citrine (compound of orange and green), 19; russet (orange and purple), 21; olive (green and purple), 24—integrally as 64."
In commenting on this in "The Theory of Color" Dr. Von Bezold says: "It is often maintained that the individual colors in a colored ornament should be so chosen, both as regards hues and the areas assigned to them, that the resulting mixture, as well as the total impression produced when such ornaments are looked at from a considerable distance, should be a neutral gray. Starting from this idea, the attempt has been made to fix the proportional size of the areas, which would have to be assigned to the various colors usually employed in the arts, for the purpose of arriving at the result indicated. This idea was especially elaborated by Field, an Englishman, who gave the name of 'chromatic equivalents' to the numbers of the proportions obtained, a designation which has since been very generally adopted. In reality, however, these 'chromatic equivalents' have no value whatever."
The same writer also says: "It will always remain incomprehensible that even a man like Owen Jones in the text accompanying his beautiful "Grammar of Ornament" should have adopted this proposition in the form given to it by Field, since among all the ornaments reproduced in the work just mentioned there are scarcely any which will really show the distribution of colors demanded by the proposition in question." [B]
In accordance with this eminent authority any one familiar with disk combinations will know by experiment that no combinations of red, yellow and blue approaching the proportion named by Field can produce a neutral gray effect in the eye.
Colored Papers.
For practical study of color some economic material is absolutely necessary and nothing so well combines manual work with æsthetic cultivation as colored papers, if specially prepared in standard colors and with a dead plated surface.
In the manufacture of the colored papers adopted in the Bradley scheme of color instruction, the effort has constantly been to produce the closest possible imitations of natural colors consistent with the material.
With this aim in view we have secured the brightest possible red, orange, yellow, green and blue and have chosen a violet which has the same relation to the other pigmentary colors that the soft beauty of the spectrum violet bears to the other parts of the spectrum.
It however happens that in the pure aniline colors discovered in recent years a line of purples and violets has been found so much purer than the other pigments that we cannot with our red and violet make a perfect imitation of the brightest aniline purples used in some of the goods now in the market. Purple is a general name for the several modifications of violet, red-violet and violet-red as Peacock Blue is a name given to the beautiful hues of blue-green and green-blue. These aniline purples are but another indication that we may expect such advance in the science of pigment manufacture in the comparatively near future that a much purer line of standards may be secured than is now possible in papers. But it does not materially affect the value of the present standards as long as they are accepted as indicating the kind of color, i.e., its location in the spectrum, and the artists certainly should not object to this lack of purity, because their only present criticism is that the standards are too "raw," which is but another term for pure.