This isn't in the white but close to it, blue rubbed back to gray, I found gray to be the least durable of all the finishes you can put a firearm because it literally rubs off over time.
This about 10 years down the road from what was a gray finish, the barrel has been kept well-oiled but the patina formed anyway and I like it. 220 grit sand paper was as fine as I went on this barrel.
The finish started like this;
The gray is mostly gone and the barrel looks like this now;
A couple more pictures, I left the lock bright on this fowler and went to 000 steel wool on it.
As just finished;
This morning, the polished lock stayed bright.