well if you do aircraft you are in luck... Color of Eagles paints are sold by Great Models and are made by Vallejo. It is an almost complete collection of colors used in WWII and after. For some reason they don't have the Japanese colors yet though...
If you are looking for other Vallejo paints (the ones that actually say Vallejo on them) then I have only seen those on ebay stores, I know there are a few places that sell them but you'll have to do a google search like "vellejo paint buy" or something like that. This question came up awhile back and I know there is a hobby shop out in CA somewhere that sells them online.