You should be okay. You had just one potato of 8oz, not all of which was green. You’d have to eat a fully-green 1 lb potato (equivalent to a large baked potato), to get sick. This sounds more like trace amounts - which may cause some uneasiness (at worst a headache and some mild stomach/gut pain) but not make you go to the ER. Your body will flush it out naturally in the coming days.

Don’t eat any more potatoes that look even remotely green, from now on.

And if it was pre-wrapped, contact the company that packed them and give them an earful.