Yes, they were anodized. The flat ends and the outer edges of the fins were bare, not painted. In between the fins was painted dark gray. A very difficult job to recreate 'em just right.
There used to be a retired Chrysler engineer in Mich that did them, but that has been years ago. Roger Gibson turned me on to him. And then they came back with the little rock chip dimples still in the ends.
I have always been curious who cast those things. The only cars I have seen them on were the '71Xs, AARs and one of the AMC muscle cars, maybe the AMX.