what color would the ditch light on this be considered?

[Stan]

NS4148 GP38ac

I know the frame is usually black, well before its all rusted. But the frame around the lens is aluminum, silver? Just trying to figure out what color to paint the round part.

[ssgburme]

Cast aluminum
Karl

[ladderpipe]

NSer, ssgburme is correct but make sure you take a peek at proto pics. The only reason i say that is because some NS locos have the ditch lights painted black and some of them are not painted