Pasty face? Or do you mean Pastel-faced? Chances are he is molting into some adult feathers at that age. Keep in mind Australian (and African) birds are generally dustier (meaning the produce more dander) than birds from South America for instance. So you'll often see little feathers and dander/dust around the cage. It's fairly common. So long as he is still behaving normally, eating drinking, etc. I wouldn't worry too much. You can offer supplemental heat near the cage and increase offerings of soft food (such as eggfood you can make at home that is more beneficial than storebought) in order to give him some added protein.
