Greenish Japanese Sweet Potato after cooking

Hello! I am newer to eating japanese sweet potato and I made one for lunch (baked at 400 F, sliced open, mashed middle with butter) and stored it in an airtight class container. I ate some of it but am scared that it maybe was bad but hoping it was just oxidation? Google doesn’t have much on this. Please help, i’m scared i’m going to get sick 😅