My sister has a ring which she is insistent is platinum but it looks to me as if the underneath (the part of the ring that you can see when looking at her palm) is turning ever so slightly yellowy. I thought this only happened with white gold? Am I wrong? Can platinum tarnish/change colour? She's had it just over a year and wears it everyday.
Platinum won't tarnish, maybe only dull slightly over the years. It sounds as though it's white gold.
It's the Rhodium plating on white gold that wears away. She should be able to get it replated yearly, free of charge from where she purchased it. :o) x