First I would say that your story is a caution against buying materials until they are needed. Second, I believe there was a formulation tweak at some point that had no effect on the efficiency of #700, but changed the coloration and handling of the product and sure got a lot of people (myself included) uptight about the change, and since that time I think a further change was implemented and we now no longer see significant yellowing of the product, although a slight tinge can be present.
All that said, I would bet that your product is safe to use, but also that Barry would probably replace it at no cost as a matter of course if it causes concern.