I was wondering today what is the colour of pure neutrons confined together, I'd guess it's either completely black or white, because it doesn't have the electric orbitals needed to generate different wavelengths. I'm generally guessing it just reflects light and is therefore what.... maybe a mirror? And I am mainly meaning the matter neutrons confined, and disregarding that electrons may be flowing at the outermost layer of a neutron star. So what is the colour of pure pressurized neutrons, but what about the neutrons star like it is inclunding the electrons flowing around and such? Are there any studies done on this?