Quote Originally Posted by polyglot View Post
Brown staining on film is a sign of underfixing, which (if that's what you've done) means your negs will degrade rapidly in storage. You should re-fix them ASAP so that they're properly cleared.
Correct me if I'm wrong, but I believe Gerald was referring to the colour of the silver that forms the image of the negative rather than stains caused by underfixing, which you won't see until the negatives are at least few weeks old. Some developing agents like pyrogallol naturally stain the film. http://en.wikipedia.org/wiki/Pyrogallol

Welcome to APUG, Markman. :-)