It is not the specific gun bluing coin I mentioned.
The coin is an ancient bronze, I would think that any color you get from ancient bronze
sculpture or other object, you could get with a bronze coin.
So you might look at
bronze objects with what their coloring is.
Patina, I believe, is an oxidization that protects the object, whether it be silver or bronze, unlike rust which is an oxidization which damages and eventually destroys iron objects.