Share on Xa) The characteristic of the visual sensation that enables the eye to distinguish differences in its quality, such as may be caused by differences in the spectral distribution of light rather than by differences in spatial distribution or fluctuations with time.
b) As (a) above, but applied directly to the stimulus or the source (primary or secondary) giving rise to the sensation. (For brevity, the stimulus is often referred to as the colour).
c) The property of an object or stimulus or quality of visual sensation, distinguished by its appearance of redness, greenness, etc., in contradistinction to whiteness, greyness, blackness (i.e. chromatic colour is contradistinctinve to achromatic colour).
