Different NES revisions actually output different colors. Plus, originally it's an RF signal, then composite. It was displayed on some CRT. It's possible to RGB

Different NES revisions actually output different colors. Plus, originally it's an RF signal, then composite. It was displayed on some CRT. It's possible to RGB mod an NES, but is that authentic? No. The one true color of Luigi is the one that you saw as a child on a sunday afternoon in the eighties. Lost in time, like tears in rain.