This isn't a ferret-specific thing; it actually is a study of black
pigment tagging along with a very important health protection in cat
species, but it gives a good feel how playing around with genetics on
things that *seem* superficial might accidentally lead to undesired
consequences:
http://www.wired.com/news/medtech/0,1286,57883,00.html
 
Bill, it is up to you whether to include it.
[Posted in FML issue 4077]