I think that sable is a dominant gene. My friend has a sable boy and was told by his breeder to put him to chocolate and she would get sable pups. Not sure how it works exactly witout reading about it properly, even though I did genetics at uni!!!
There is a sable particoloured dog somewhere in the UK I think imported from Sweden or Germany and she is the first parti sable in the UK. Can't remember the website, will have a look and get back!!