I've read that this red or plum color can happen with hot salts bluing when the temperature of the bath is not correct, particularly with steels alloyed with nickel. The green color is something I have never heard of. I have an unfired Mauser Model 66-S with .30-06 and .243 barrels which has turned plum colored only on the receiver ring, but the rest of the action is still deep blue/black.
I'd like to know if there is some way to reverse this, or even if it could be put back into a bluing tank without stripping the original blue, because I had read about discolored parts being put back into the bath at higher temperature in one of the editions of Brownells "Gunsmith Kinks".
