I think the problem is chemistry, not math. If you don't start with phosphors with the right behavior, you can't combine them to get the result you want. Speci

I think the problem is chemistry, not math. If you don't start with phosphors with the right behavior, you can't combine them to get the result you want. Specifically, the math breaks down at "subject to all concentrations being >= 0". This is exactly the same reason you can't generate all visible colors from RGB or CMY (http://en.wikipedia.org/wiki/Gamut http://en.wikipedia.org/wiki/Gamut) - there are colors outside the linear combination of the starting values. And the problem is much worse here, because the number of dimensions is much greater than three. (You also have to assume the mint will watch purchases of the necessary phosphors.) For reference, the relevant patent (via SO) is https://www.google.com/patents/US20110305919 https://www.google.com/patents/US20110305919