True it is…

Yes at exactly 0K and without quantumechanics…

Yoy can filter out frequencies in the rainbow spectra in a way that it looks like any color…

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.

Naah… Its just confusing spectra with perception… We may only perceive 72% of the spectra… But the rainbow it self has all the colors…

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…

For me, it reads like old people doing old people things. Let’s see how it plays out.