There is so much variation in shell color that having a perfectly matching belt and shoes is almost impossible. And, even if it weren't, there would be no reason to perfectly match. So, you're fine. Accepting that advice will keep you from going crazy.
Shoes being treated like shoes. Love it. While I can't quite bring myself around to accepting ware and tare (or is it wear and tear), I do appreciate it when others can. (Though the writing on them goes a bit far, even for me.)
I hope you keep enjoying them.