Sure polar fox have dark pigment on their tail.
Although, they're not usually described as "pure white". My only other
guess would be champagne but those usually have orange spots on the
head. Are you sure the father is slate ie did you get him from a breeder
vs. a pet store and if a pet store, are grey agoutis common in your
area?
Eizabeth
--
Secretary of the American Gerbil Society
http://www.geocities.com/Heartland/Shores/8181/AGS/
Breeder of healthy, colorful gerbils * Devoted Earth2 Fan
* Visit http://www.voicenet.com/~heckercw/elsewhere/ *
for more information about Earth2, my gerbils, Pomeranian & graphics
Specializing in: grey agouti and polar fox gerbils - wide range of
others too
Proud Member of E2:EA, GCM, & AGS - Proud Pom-Mom to Foxy!