Wow! It's amazing that you got so many different colors - isn't genetics fun? Would love to see pics.
My Chin doe's first litter was sired by a REW NZ buck, and all kits look just like mom - chinchilla. She had 7 healthy kits but I don't think her milk came in right away and 3 died. The other 4 only survived the first week because they were fostered to another first-time mom who kindled at the same time, a NZ/Silver Fox doe who already had 7 of her own to feed, for a couple of days. That was a new one to me.
I have a proven black SF buck and a new (unproven) lilac SF buck. I found that the black buck just doesn't like one of my REW NZ does...he would not breed her in multiple attempts, but when I put a (also new) black SF doe in with him, it was a completely different story. I was very surprised, since he hasn't been the most enthusiastic breeder - he really liked the SF doe. I guess everyone has their preferences! lol Is your black SF buck better with other does?