Hi xwing! ,
It's straight polyurethane from the factory, but when I bought it I had them paint it with a latex based flat black paint that matched OEM perfectly. GT3Tek/Better Bodies did the install and paint for me, so I'm not 100% sure what the brand of paint was, but I'm sure if you asked they could give you a good recommendation. Whatever they used it has held up great so far!
Cheers,
Code
(aka Josh)