Every panther loacale is slightly different. There is data (although old, and possible outdated, if climates could change at all since it was written) on the specific temperatures and humiditysof many popular panther locales. It is possible that Ankaramys tend to be more specific, and picky to theirs and although they might adapt OK to watever they are being given, they may require something more finely tuned for breeding- to mimic that of the wild location. That being said its only really rare to find CB ankaramys because so few WCs were brought in- minus the deaths, minus the people who dont give good enough care, etc.
If you havent noticed you can see slight differences in between the locals not only in colour. Body proportion can vary greatly.