This is normal. Once you baby starts consuming more milk, their stools will be more grainy and mustardy.
Hi... you might find this article informative https://sg.theasianparent.com/baby-poop-guide
It sounds OK to me...Do see a pd if you're worried but green poop in babies is not unusual(:
I hope this article helps: https://sg.theasianparent.com/baby-poop-guide