Discoloration of Silicone Seal on Pump

Hello, I’m new to posting, but not new to lurking these boards. I’ve been lurking for 2 years till I decided to post. I bought a LongJohnny tube and pump quite some time ago and took a few months break from use. After moving to a new place, I unpacked my pump and discovered the silicone seal now has pink spots! Light seems to shine over them, so it has seeped into the material somehow. Does anyone have any experience with this sort of damage and is my seal still safe to use for pumping in the future?

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