COLOR TERMS
120. In the study of color and its application authorities differ so materially that it is not only impossible to reconcile their theories, but the different terms used to express color thought create inextricable confusion.
121. One authority fixes the neutrals as being black, gray and white; another regards them as those hues or tones which lack definite color, like quaternaries. Authorities differ, moreover, upon even the fundamental principles. Chevreuil selects red, yellow and blue as the primaries; Dr. Thomas Young selects red, green and violet. Helmholtz selects carmine, pale green and blue-violet; Maxwell scarlet red, emerald green and blue-violet; Professor Rood agrees with Maxwell; Professor Church, of the Royal Academy of Arts, London, regards the primaries as red, green and blue; George Hurst, the English authority, fixes upon red, yellow and blue, the Brewsterian theory.
122. One must remember always in studying color that we are treating with the material, not with the illusion. We are dealing with pigments, not with prismatic phenomena, and it must be obvious that the only three primary colors that can be used in a way to produce all other colors are red, yellow and blue.
123. Whatever may be the spectrum theories of Sir Isaac Newton, Young or Helmholtz, for practical reasons we prefer to follow an authority as eminent as Chevreuil, for years the head of the National Gobelin Works of France, and a man experienced in the practice as well as the theory of color. Any effort to fix the character of color and describe it by periods and epochs will always prove unsatisfactory, for the reason that terms and expressions have changed with every period since the Egyptian, 4000 B.C.