I think don't even understand the point of the author.<p>For one, I learnt in school that the primary colours where red, green and blue, and later that the substractive primary colours where cyan, magenta and yellow. So nothing different from the RGB/CMYK colour wheels everyone uses.<p>Second, well nobody will ever be able to create all colours from mixing red, yellow and blue, plain and simple. Unless your red is actually magenta and your blue is actually cyan.<p>At this point, you have just created a colour picker that uses cyan, magenta and yellow with no easy way to change lightness (without the K scale, you will have to manually change every colour level to match the global lightness you want).<p><i>But</i> his implementation has a brightness slider and uses "real" red instead of magenta, and "real" blue instead of cyan, which makes it a BMYK color wheel, and which prevents it from reproducing all colours. Even just setting brightness to the minimum gives a dark brown instead of black, because he's mixing colors from different models.