I'm very interested in colours just now because the French Club of our breed (I have Brittanys) has just banned sables saying that it must have been brought into the breed via a misalliance. I'm unconvinced, thinking it is more likely to be a mutation. It's not banned in the UK as yet although tricolours have to have specific markings - above the eyes, on the cheeks, below the knee and on front legs, either side of chest, and under vent. I don't understand genetics but find it fascinating and am trying to trace back the earliest incidence of sable in the UK. It appears to have come from France when the breed first came into the UK.