Question

How to make greener than green or blacker than black?

Answer 1

The green colour appears when all the light of the visible spectrum is absorbed by the object except green. Then, the object appears to be green. The green colour appears to be greener if the spectrum of the light reflecting all the green wavelength after falling on it. So, by making reflecting green light spectrum more we can make green colour greener.

The black colour appears to be black when all the wavelength of the visible spectrum absorbed by the object. Then, the object appears to be black. The black appears to be blacker by making it absorbing all the light falling on it. For example, Perfect Black Body is the best example of it, whatever light falls on it all get absorbed.