Gold iridite/dichromate, not painted. My originals have faded quite a bit, but the original finish remains visible after all these years. If you are refinishing a booster, there are several people that do a great job of restoration/rebuild, like Steve Gregori. Some reproductions I've seen over the years are too bright and/or too shiny. originals are more of a matte that I have seen (other opinions ?).
Regards,
Steve