putting blue dye in blue/white UV dye most likely wont make it glow any better. also, most Antifreeze already glows green, so you dont need to add green UV dye to it.
to GenGoko:
that is a blacklight. the cold cathodes are flourescent lights. the blacklight version is the one you want; the others ('red', green, blue, etc) will just cast colored light. you can get 4 inch CCs (including UV CCs) from ZXmods for
$11 a piece. 2 or 3 of em would be plenty. or, one 12 inch from ZXmods or PCmods, mounted vertically, would also work.