A further problem is that I don't think the so called colour terms convey only the meaning of hue; I haven't really studied the question myself, but I think sometimes the main idea these colour terms convey isn't really colour but something else like warmth, texture, brilliancy or gloss. In Homer, we have for example μέλαν ὕδωρ, and also we have λευκός applied to ὕδωρ and πολιός applied to the sea. Whatever these exactly mean I'm not sure although I could have a guess, but "black", "white" and "grey" would be too simple in my opinion. I also wonder whether for Greeks "black" and "red" blood had different shade of meaning (fresh, especially arterial blood is not as dark as venous blood or clotted blood, etc.).
Without having properly studied the question I suspect that the "technical" conception of colour is typically Western peculiarity; I mean the idea that the visible spectrum can be cut up into great number of clearly defined segments and each assigned to colour term without much overlap, while the colour terms themselves have not imply much more than a particular hue, i.e. they say nothing about warmth, gloss, texture etc.