Red Colored Brass?

[Tubajug]

I'm curious, my school has a Bach Mercedes tuba like this one on da Bay. This one and the one where I teach both are almost lacquer-less, but the brass has that red tone to it after so much wear. I haven't seen that on any other tubas I've seen. It is something about the Bach brass?

[Dan Schultz]

There's nothing unusual about that color of patina. It depends on the type of atmosphere the tuba is exposed to more than the content of the brass.