Those jigs have a white base coat. I don't see pearlescent effect except on the white one (probably screen). You can buy a pearlescent additive to add to powder paint. Try Powder By The Pound or Columbia Coatings. If you want to try some fun stuff check out "illusion" powder paint.
Pretty sure you can get an additive for regular paint also. For fingernail polish I think they call it a satin finish.....