Color

Characteristic effect of light dependent upon the wave length. Sunlight is composed of rays of many different colors varying from the red, which has the longest wave length, to the violet, which has the shortest. The color of objects is directly dependent upon the kind of light that they reflect or transmit to the eye. Subjectively, it is a sensation arising from stimulation of the optic nerve by light radiated from a luminous body or reflected from a non-luminous body or by some mechanical stimulus, e.g., pre ure on eyeball. Ob white light analyzed into parts of definite wave lengths shows the colors, red, orange, yellow, green, blue, indigo and violet. (See SPECTRUM.) These colors are termed primary. Psychologically, black and white are also to be regarded as colors. Colors vary, in hue, according to the wave length of the light, in brightne , and in chroma or the amount of white light entering into them. A color is said to be saturated when it is free from admixture of white light.