Does copper migrate through silver?

COuld it have been extremely thin silver plating that has worn off with usage of the receptacle ?
Also silver tarnishes (silver sulphate) ... perhaps it's just tarnish you're seeing ? I don't think copper will migrate through silver at room temperature.

Psychicanimal, let me know what ever you find out. I've been using mine for about the some length of time with no discoloration.

what color is your fridge? after a similar burn in ( the equivilent of 27 years in duration) all my cryoed recepticals are now avocado. is there something sinister going on here? FWIW, we have a stainless steel sub-zero.

-cfb