﻿On Color. 



169 



Primaries. Secondaries. Tertiaries. 



I. Yellow, . IV. Orange, . . VIT. Citrine, . 

 II. Red, . . V. Green, . VIII. Russet, 

 III. Blue, . . VI. Purple, . . | IX. Olive, 



The arrows indicate the manner in which the colors are combined ; i. e., 

 how the secondaries are derived from the primaries, and the tertiaries from 

 the secondaries.* 



The following diagram shows the relative amount of superficial space 

 each color should possess, in order to form an harmonious combination : 



VII. Citrine, 

 VIII. Russet, 

 IX. Olive, 



I. Yellow, . . 1 IV. Orange, . 3 

 II. Red, 2 V. Green, . . 4 



III. Blue, . . 3 VI. Purple, . 5 



The numerical values attributed to the spaces occupied by the colors 

 as derived from the solar spectrum, are given of different values by writers 

 on optics; but for practical purposes, the numbers one, two and three give 

 relations that are satisfactory for all our purposes, and readily remembered. 



Now, combining these colors by algebraic symbols, we get the following 

 diagram : 



VII. 2 Y.-j-B.+R=rCitrine. 

 VIII. 2 R.-f Y.+B=rRusset. 

 IX. 2 B.+Y.-fR=01ive. 



I. Yellow, IV. Y.+R.=Orange, 



II. Red, . V. Y.-fB— Green, 

 III. Blue, . VI. R.-fB.=Purple, 



A simple idea of the tertiaries can be obtained by considering them all 

 as grays ; for the citrine is a yellowish gray, russet is a reddish gray, and 

 olive is a blueish gray. A pure gray is a true neutral tint, made up of 

 all three of the primitive colors, in such proportions that no one of them 

 is perceived to preponderate. 



* Any vertical row of colors is deduced from the row on the left, by combining : 

 The first and second to form the first. 

 The first and third to form the second. 

 The second and third to form the third. 

 Thus to form the secondaries: 



We combine yellow and red to form orange. 

 44 " blue " green. 



" red and blue to form purple. 



And when we wish to form the tertiaries : 



We combine orange and green to form citrine. 

 " " purple to form russet. 



" green and purple to form olive. 



In my diagrams and formulae I had arrows drawn, which by the course they 

 pointed out, designated the manner of mixing the colors; but, as it would be diffi- 

 cult to represent the arrows in type, I hope the above explanations will prove to be 

 sufficiently clear to be understood. 



