Here you can generate Punnett Square diagrams to get an idea of how colours and markings work. Just select the parents and off you go!
Breeds
Mother: Aquila
Father: Aquila
.
Colours
This is a simplified calculator. It does not include shade alleles, nor colour-shifting mutations, so keep that in mind when actually breeding - you may get something lighter or darker, or a coat that appears radically different, depending on the parents' genes.