of the color of the spectrum
between wave lengths .505 and .415 micron, and more especially .487 and
.460; or of such light mixed with white; azure, cerulean.

BLACK.--Possessing in the highest degree the property of absorbing
light; reflecting and transmitting little or no light; of the color of
soot or coal; of the darkest possible hue; sable. Optically, wholly
destitute of color, or absolutely dark, whether from the absence or the
total absorption of light. Opposed to white.

BROWN.--A dark color, inclined to red or yellow, obtained by mixing red,
black, and yellow.

+CHROMA.--The degree of departure of a color sensation from that of
white or gray; the intensity of distinctive hue; color intensity.+

CHROMATIC.--Relating to or of the nature of color.

COBALT BLUE.--A pure blue tending toward cyan blue and of high
luminosity; also called Hungary blue, Lethner's blue, and Paris blue.

COLOR.--Objectively, that quality of a thing or appearance which is
perceived by the eye alone, independently of the form of the thing;
subjectively, a sensation peculiar to the organ of vision, and arising
from the optic nerve.

COLOR BLINDNESS.--Incapacity for perceiving colors, independent of the
capacity for distinguishing light and shade. The most common form is
inability to perceive red as a distinct color, red objects being
confounded with gray or green; and next in frequency is the inability to
perceive green.

COLOR CONSTANTS.--The numbers which measure the quantities, as well as
any other system of three numbers for defining colors, are called
constants of color.

COLOR VARIABLES.--Colors vary in CHROMA, or freedom from admixture of
white light; in BRIGHTNESS, or luminosity; and in HUE, which roughly
corresponds to the mean wave length of the light emitted.

COLORS, COMPLEMENTARY.--Those pairs of color which when mixed produce
white or gray light, such as red and green-blue, yellow and indigo-blue,
green-yellow and violet.

COLORS, PRIMARY.--The red, green, and violet light of the spectrum, from
the mixture of which all other colors can be produced. Also called
fundamental colors.

DYESTUFFS.--In commerce, any dyewood, lichen, or dyecake used in dyeing
and staining.

ELECTRIC LIGHT.--Light produced by electricity and of two general kinds,
the arc light and the incandescent light. In the first the voltaic arc
is employed. In the second a resisting conductor is rendered
incandescent by the current.

ENAMEL.--In