The space of visible colors is three-dimensional, and the spectrum is missing two dimensions (brightness and saturation). You canβt assign a percentage to that.
Well there is wavelength and intensity, an all together it is called a spectrum. No need for a third parameter.
Also there are mor than 100% of all colors in there, as a quick check on Wikipedia would reveal..
There is no such thing as a mono wavelength color. There are only spectral densities. Or in other words electromagnetic radiation / photons distributed over some energy.