The color of the discharge is insufficient to say whether it is normal or not. The consistency, the amount, the odor, the associated symptoms, the pH, underlying illnesses etc are to be determined too. However the discharge during the pregnancy is copious,white and slimy which is normal. The greenish yellow discharge signifies infection. If there is any color tinge or spotting, or if the discharge is thin and clear before the 37 weeks of pregnancy please see the Obstetrician.