Newborn urine is usually clear and slightly yellow. Indicator lines on most disposable diapers can help you know if your baby is wet. You may not be able to see the urine. Sometimes, newborns have pink urine that is confused with blood. Do not be alarmed. This is very common. The pink color is from pyruvate crystals, which can be seen in the first 3-5 days after birth when babies are not yet gaining weight. The pyruvate crystals will stay pink in color, as opposed to blood, which will oxidize and turn dark maroon or brownish in color. The crystals go away as the infant takes in more milk.