What’s wrong with the light red color on my baby’s diaper? During the first few days of life, your newborn baby’s urine happens to have a light red color, slightly cloudy, with reddish-brown or yellowish-brown deposits, which are crystals of urates. These are urate crystals, which usually turn lighter after a few days, so this is often a normal physiological phenomenon. In addition, if the baby eats milk and the mother eats colored medication, such as rifampin, or eats beets, which causes the mother’s milk to appear light red, the baby will also have red urine after eating, but this urine test has no red blood cells and is not true bleeding in the urine; and red urine if it is hematuria caused by bleeding in the urine, then the baby should be sent to the hospital to check if the urinary system is infected with nephritis or something like that symptoms, which generally should not be the case.