Etymology: Middle English colour, from Anglo-French, from Latin color; to conceal or to hide.

In physics, a property inherent in light, which, by a difference in the rays and the laws of refraction, or some other cause, gives to bodies particular appearances to the eye.

A phenomenon of light or visual perception that enables one to differentiate otherwise identical objects.

(1): the aspect of the appearance of objects and light sources that may be described in terms of hue, lightness, and saturation for objects and hue, brightness, and saturation for light sources such as the changing color of the sky,

also : a specific combination of hue, saturation, and lightness or brightness.