It’s easy to think that a green orange is unripe, but that’s not the case. Australian oranges available at this time of the year, are the valencia variety. They often have a green tinge to them, which makes them appear to be unripe. The green tinge is a defense mechanism designed to protect the inside of the orange from the harsh summer sun.
Valencia oranges are in season now, and are more suitable for juicing than the navel variety which is the winter orange variety.