Brian has 1 black nail on both his front paws and 2 on one of his left back foot but none on the right foot.  Ein, my red/white boy has white nails.  Edit: Oh, and Brian's nails were white when he was younger.  
I've been wondering for a while, why only some of Brian's nails were black?  
Two possible reasons came to my mind:  
1. Brian's a black headed tri and wanted his nails to be tri color too.
2. He got a bruise on the nail (if that's even possible)? 
Any ideas?