[Hoodshaker]

I can't say with 100% certainty, but when I did mine I painted them the same "chassis black" that the subframe and other engine brackets got, since I believe that's the way they came out of the factory.

Today, looking at other original brackets, especially around bolt holes and on the backside that faces the block, suggests the same. https://www.ebay.com/itm/295201592056

Edit-looking back at my photos after I cleaned off a couple of layers of paint from previous owners, I was left with some traces of black paint at the base surface- https://photos.app.goo.gl/nRnTqRqk39injJyv7