Fox Collectors

I have a 12 ga "A" grade Fox with Krupp barrels auto ejectors and two sets of barrels patent 1911 and all the numbers match. The thirty inch barrels I don't think have ever been used and are a standard blue. The twenty eight inch barrel set has one brown and one blue. I can think of several reasons for this but I don't know for sure. So my question is do I have an odity and did the gun leave the factory this way or did someone reblue the barrels at some point and mismatch the coloring?

Try to post some good pictures of the barrels. Bobby