Yup, all the time. My most exciting random things to come out of my colony were 1.2 solid black rats, tail, belly, paws and all, and a 0.1 solid blue. Actually, the blue came out of my solid blacks, who produced a litter of 8: 1 blue, 1 solid black, and the rest albino. Go figure.

My other favorite ones recently are two solid white females with black eyes and a faint black dot on their back, one has a tiny black "smudge" above her right eye. Those are definite hold backs!