Question

Two students are discussing the physics of color. The students are claiming that white and black are not really colors of light. If white and black are not really colors of light then what are they?

Answer 1

Every body absorbs some wavelengths of light and they reflect remaining wavelengths (e.g. if a body reflects red wavelength of light, then object appears red).

But some bodies do not absorb any wavelength of visible light, They reflect all, Hence we get the mixture of all wavelengths of light(VIBGYOR),And it is what we call as WHITE color.

In the reverse case some bodies absorb every wavelength of visible light, and reflect none, Hence we do not see any color, Hence it appears BLACK.

BLACK is actually deficiency of color, It's not the actual cololor.
While WHITE is the mixture of visible spectrum of light(VIBGYOR).