PRINCIPLES OF COLOR. 
21 
Without thought of improving upon the above arrange- 
ment, the author would nevertheless present the following 
classification, as perhaps a more convenient one for the 
purposes of the present work. 
I. Pure colors of the solar spectrum. 
a. Primary colors, or those not produced by mixture. 
1. Eed. 
2. Yellow. 
3. Blue. 
b. Secondary colors, or those produced by the mixture 
of two primary colors. 
4. Orange {— red + yellow). 
5. Green (= yellow + blue). 
6. Purple (= blue + red). 
II. Impure colors, or those not found in the solar spectrum. 
a. Shades, which may consist of either primary or secon- 
dary colors 1 darkened by black (= complete or absolute 
shade). 
b. Tints, which may consist ot either primary or secondary 
colors lightened by the admixture of white (— absolute 
degree of light). 
c. Subdued colors, which consist of combinations of two 
or more secondary colors, or of a secondary color with 
the primary which does not enter into its composition, 
that is, its complementary color, as green with red, 
purple with yellow, orange with blue, etc., — the effect 
being to subdue or neutralize the colors which are thus 
combined. 
1 The principal shades may be classified as follows : — 
a. Shades of primary colors. 
1. Of red (— red + black) — "maroon." 
2. Of yellow (= yellow + black ) = "olive." 
3. Of blue blue + black) = "indigo" or "blue-black." 
b. Shades of secondary colors. 
4. Of orange (= yellow + red -f black) = brown. 
5. Of green (= yellow -f blue + black) = dark green, "bottle- 
green." "myrtle-green." 
6. Of purple (= blue + red + black) — "plum-purple." 
