Colour Gamut, G-a-M-U-T

Colour theory is a whole huge field of itself and trying to find your standard reference colour is really hard. What you'd need would be a colour vision specialist who deals with a thing called a gamut, G-A-M-U-T. There's a gamut for light, or colours created by light and there's a slightly different gamut for colours created by dyes but they don't quite overlap.