I found out about the color change Mike is talking about the hard way! I loaded up some black with the UV. In the shop they looked great so I kept popping them out. 500 baits later I took one out in the sun to find the black looked purple.
Lureworks has a great UV additive. You don't use very much at all. If you use too much, it's going to give the clear plastic a little bit of a blue hue. But under a black light your baits will glow like a white t-shirt in a disco.