Green poop is the internet's most Googled baby health question. Here is what each shade means at each age.
Newborns: Meconium is dark green or black — totally normal. Breastfed babies: Yellow or mustard-colored is normal. Green can mean foremilk/hindmilk imbalance. When solids start: Green veggies like peas can turn stool green.
When to call the doctor: White or clay-colored stool, red or black stool (not meconium), or green with mucus and diarrhea.