Doctor said to wait and see what the next poop looks like
My baby poops the same color , my doctor said that it’s sometimes normal but they sent me to collect his poop just in case to run some tests , but she said not to really worry unless I see blood or it’s like a light gray , but definitely keep track and keep taking pictures so you can show your doctor
from the edges, that looks very dark green. i'd suggest getting a wipe and putting a little on it and smudging it around to see if it's actually gray or if it's just dark
Call her doctor and see what they recommend.