What is the definition of a color?
A. Colour is the sensation produced in response to selective absorption of wavelengths from visible light. It possesses the attributes of Brightness, Colourfulness and Hue. An international standard developed by CIE can be used for measurement of these attributes for any colour. An alternative way of specifying colour is to refer to a colour order system such as the Munsell or NCS systems. The Munsell system contains colours of varying relative colourfulness and brightness for the 20 hues defined. The CIE tristimulus values for the Munsell colours have been published (see Color Science by Wyszecki and Stiles – published by Wiley, for example).