Curt - yes, the inside of the housing. The ones on my car as well as the one I am using as a replacement just seem to have been painted silver. But who knows what has happened to these pieces over the past 29 years.
The thing that makes me think they may be painted is that when you look at the rears there is a small "chrome" piece behind the turn lamp but the rest of the housing seems to be painted like the fronts.
tm