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]