A baby’s green-colored stool can be normal. Breastfed babies usually have green or dark green stool, while formula-fed babies typically have yellow stool. Adding new green vegetables or fruits to the baby’s diet can also turn the stool green. If the baby’s frequency and characteristics of defecation are not significantly abnormal, and the baby is in good spirits, eating well, without symptoms such as fever, cough, or vomiting, no special treatment is needed.