kids school chairs {looking for ideas}

I just picked up 4 of these kids school chairs (for free!!). They are cuter than the picture shows as the legs are actually a cute grey metal. Anyhow, the seat and back definitely need to be painted since it's pretty worn. They are a slick fiberglass (?) or something like that. (Just think of your elementary school chairs.) What'd the best paint to use? Will the spray paint that I'd made for plastic outdoor chairs work? Thanks for any and all suggestions!