If your trying to go for a tint, use a Candy paint. If your not to knowledgeble on mixing candy basecoats and clears and such, Duplicolor offers products called METALCAST, in red, orange, green/turqouise (I believe), Purple and yellow. VHT, a sister company with Duplicolor, offers a product called nightshade, intended for tinting tailights, so that gives you a clear black tinted finish. If you sand the plastic first you WILL see the scratches through paint, just pick up a can of adhesion promoter for plastic. Duplicolor, and bulldog make a good product.
bribe them with alcohol and large sums of monopoly money.
in all seriousness, stock elite guns aren't to shabby, but if they are concerned about safety just let them examine your blaster. If its getting owned they're worried about, send them a link to the mod reference guide. if they still have problem, theyre either lazy, stubborn, or related to vincent van goh.
If your really crafty you could modify the members of your groups blasters for money! good luck mate.