Interesting.
What they're basically doing is creating a paint with their pigment powders and using that to glaze on the effects.
I do those same effects on the engines of my X-Wing ships, but with simple Vallejo dayglo paints, which do exactly the same. So instead of trying to get hold of those powders and then medium etc, why not just get yourself some ready made paints/glazes?
I'm not convinced by their blue though; I still use standard paints for that, but the magenta, orangeand yellow are very effective indeed. Haven't tried the green yet...