Talk to Pediatrician on Baby Passing Stool Of Green Colour

My 5 month old baby is passing stool of green colour and it has been more than a week now. His milk intake was v low from the beginning and he has been certainly underweight (although he was born a healthy child ) so on his paediatric’s recommendation I started giving him semi solids like rice cerelac, banana shake, alo ki kheer, sagu-dana And kichri. He likes to eat all of this and has been digesting well. He passes stool after 24 hours and consistency is also fine (not very soft not very hard) but colour is green. Is it fine or he has some problem? He is very active physically mashllah and it doesn’t seem that he has some issue. His current weight is 5.7kgs.