Breed your purples together(green dragons?). Nice start colorwise I might add. You are probably going to lose a good bit of the MG you were after but breed the best f1 female back to the dad and the best f1 male to the very best cleanest MG female you can find. Breed their offspring together...if you have room for 2 spawns at a time that is.
The black female looks plakat-nice form on her though. You will get longer finned plakats most likely. Look to get very rounded caudals out of that pairing. Breed the offspring of that to the very best black/yellow HM or HMPK that you can find OR find a very good yellow HM female to preserve the Bi-color and work on his caudal.
So, IMHO, good start with the bi-colors. Just make sure not to breed any red or irid into your black line. I think that will make things messy. Your purple f1 will have dragonscale patches. If you want more dragonscaling you will have to add that in. I'd go with yellow dragons to preserve the bi-color and not mess with the purple.