If you spray paint pellets white will you loose speed.

what in gods name are you talking about

I assume that you are talking about spray painting them so you can see them in flight. You will lose speed since it adds extra weight. You won't be able to tell a difference though. The paint may hurt your barrel. If you have to spray paint them, spray paint the inside of the skirt.

are you talking about game loads?

Just get some white out and damp some in the skirt of the pellet.