Keep this handy with you. Baby poop will change colour as you BM/FM. Newborn will be black, then after you give BM will be yellowish/mustard and FM will be greenish/light green/pale green.
You might want to change the milk brand again. Due to the FM taken, baby's digestion change and react therefore after the process, poop colour change/smell. It can be like a metallic smell like iron/sulfur.
My first LO started with Similac 0 to 13 months and my second LO was Dulac but now change to Soy Based for the time being due to recent diarrheoa issue (side effect of her vaccine)
itsallabout_mytwokids