Interesting that he has the colors that are non-standard over here. Hopefully he can get some info from his dad/friend.
Yes, Javas here have single combs. Generally they are not supposed to be very big, however some of us are finding that the cockerels here in Texas seem to grow pretty big combs. We think it is due to the high temperatures we get here most of the year, and that the cockerels are compensating for the heat by growing out larger combs in order to better dissipate their body heat.