Angelfish afficionados are amongst the luckiest because of the extensively mapped genetics study done by Dr. Norton decades ago. Her research is still relevant now and accurately predicts what fry your angels will produce depending on the parent genetics. Well worth a read:
http://theangelfishsociety.org/genetics.htm
In addition this is a good overview on angels in general with some info on genetics on a basic level.
http://aquanic.org/publicat/state/il...20angelfish%22
I thought these would be essential reading for an angelfish forum
Cheers
Vincent