Here's another illustration.

I start with three blue pawns on a gray plane.

Lit with a single white light, we see the color of everything and can verify that the pawns are identical. Why?

What we see (S) is the light color (L = gray-white) multiplied with the object color (C).

For the pawns it is:

S = gray * C

since gray-white is neutral and equal amounts of RGB, it does not alter the ratios so it is a constant:

S = k * C

Therefore, what we see is the true color of the object but changed in brightness.

We can say that:

HueOf(S) = HueOf(C)

The apparent hue is identical to the actual hue, when gray-white light is used.

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Renderosity forum reply notifications are wonky. If I read a follow-up in a thread, but I don't myself reply, then notifications no longer happen AT ALL on that thread. So if I seem to be ignoring a question, that's why. (Updated September 23, 2019)