i painted my stock silver plates black. i first removed the finish with sandpaper…i guess steel wool would work too. then i covered one side with a light coat using ColorPlace interior/exterior fast dry spray enamel. i used flat black because i think it goes better with the overlay than the glossy black. i let it dry for an hour. turned them over and painted the other side. i let that side dry for an hour and then gave each side a second coat. im very pleased with the final look and the plates conductivity is as sensitive as it was before painting.
four things:
apply two, maybe three light coats as opposed to being impatient and using a heavier coat.
shake the can well and spray a bit out ensuring the spray flow is steady and even before applying to plates.
place the plates on a flat surface (to avoid running or dripping marks) with newspaper underneath.
in order to maintain the plates conductive property, i would use as little paint as possible. not sure about conductive paint or whatever but i assure you the brand i mentioned above purchased at walmart worked perfectly for me when applied with two light coats.
and if something goes wrong, remove the paint with thinner and start over.