Michelle, why is there a bias against them? Just out of curiosity, I'm not planning of going down that road myself
Truthfully, I don't really know but it always seems some colours do better than others, blue roans & tans (which I love as Meg is one) are another colour that don't seem to fare very well.
I suppose sable is a relatively new colour to the show ring in this country and its going to take a while for people to get used to and warm to it.
At some shows I've been to you can see the judge is so colour biased that when their class winners come in to challenge for best of breed or the challenge certificate and they are all the same colour.
If a judge is assessing the dogs honestly, the only time colour should come into it is when a judge has to decide between two dogs which in their eyes are of equal merit, THEN it's fair enough to have a colour preference.