Tim forgot to mention that the parents were an all black or all brown father paired with a PEW. The brown ones are the children of the black ringed mouse. The father went on to produce some patched black and white mice, but they didn't live very long. The mothers ate all but one and that one later died before it reached hopper stage.
The brown ringers are now in their own colony and their first two litters were comprised of all brown ringers. No solids or patched off spring.
Odd, but then, these were just common feeder mice that we started with so they could have been carrying a wide range of unknown hets.
Jenn