If a baby vomits after each feeding, could it be due to milk protein intolerance? the vomit is milk and not discolored.

Yes, but: It could also just be reflux, a spasm or blockage of the duodenum, or other issues. Vomiting only a milk based feeding and not electrolyte hydration liquids or other feeds would point more to milk intolerance.

Bad vomiting by baby: You didn't mention your infant's age, but if your baby is indeed vomiting repeatedly throughout the day, don't delay ; get help right now. The possibilities for considerable pathology ; consequences are too great to ignore! if your child is instead spitting a portion of every feeding, or you suspect a food intolerance, the urgency is less in seeking help but evaluation is still warranted.