So there exists a Pure Caucasian, a Pure Mongoloid, and a Pure Negroid out there? Can you identify them? Can you name a rational basis for those morphological qualities by which you know them? Is it a coincidence that the qualities you have chosen coincide perfectly with those that were largely developed by bias-motivated individuals living in Europe, Australia, and North America over the past few centuries? Why not back hair, toe length, presence of palmeris longus muscle, renal vein anatomy, positon of the sciatic nerve relative to piriformis muscle? Among the "grey" how do we know which individuals can be characterized by what (oh let's say percentage) of membership they can say to have in each category? Is such a thing useful? What is your motivation for believing so?

Which has been the greater source of error: the fairly recent hyper-vigilance so seek out sources of bias and error in research seeking so-called racial differences? Or the unconscious tendency to be blind to one's own cultural norms as the arbitrary choices that they are, and to more readily accept the value of the self-like?

As to black, white, and grey, my eyes and visual cortex zero out relative to local contrast and past a certain point will default the lightest colorless shade to white and the darkest to black. With photo-sensors, I can read the result identifying the wavelength and intensity, which will tell me if the light is black or white.