I have two colonies that aren't tame because I just can't hold and pet every mouse I have but I have one colony where every one of them has been held a lot and tamed as hoppers/runners. I start out by holding them just before their eyes open and they tame real nice. If I see one in one of the other colonies that I really like I move it to the nest in the tame colony and let them finish raising it once it's eyes open. I can't add a newcomer, male or female, to either of the other two colonies but the tame group seems to accept any young animal I introduce!
I had two shaggy mice pop up in a liter the last time I was ready to start a new colony and retire an old one. There was a male and a female so I put them in two separate colonies. The female has popped out a few with semi-long hair and so has the male, but still none with the long hair. The last litter the female produced had a really nice looking female, white with Grey rump, who has the long coat. I moved her to the male's colony which is also the tame colony. They all accepted her just as I figured they would, and now I'm looking forward to seeing what they produce.
These are supposed to be snake and dragon food! I'm becoming an addict! Somebody needs to start a Breeders Anonymous group! 
I don't care what animal you pick, they all get under your skin and we all have our favorites! I am actually having more fun with my stinky mice than with the rats but I need larger prey for my bulls!
Sorry for the ramble, but someone has to stand up for the smelly little darlings!
Marcia 