Hey Buc. The two colors are Sea Mist Green and Dull Aluminum. You are correct on that the tank mount base is Dull Aluminum only on the visible portion. The non-visible portion is Sea Mist Green. The mag advance lever is also Dull Aluminum on the aluminum "handle" part. The steel lever part I don’t think was painted at the factory, but I prefer to paint it to prevent rust, plus it looks better painted. That’s it for Dull Aluminum parts.
I have had good success with the Reprotint Paint. It is expensive, but so much work goes into a good paint job that it would be a shame to use cheap paint and see it get ruined.