They are as cast pot metal. No plating on them at all (unlike the front turn signals which are plated).

Mine looked very dirty and stained with what appears as big water stains. Using my bead blaster and fine glass beads gave them a good going over and they come out as new. However after a couple of years they have tended to somewhat revert back to a stained look,,,,,but still much better than before blasting. Will do again someday.

Do not paint them. They will look highly improper. I have seen them that way.