I thought the text from Oren Kem from The Complete Collie 1952 was VERY  interesting.
 
"If you will study the history of the breed, I think you will find at one time or another that both the tri and the blue were held in low regard and almost threatened with extinction by the dominating sables.  In those instances, an informal or, in one case, a formal organized group gathered to preserve them and with their efforts obtained an end to discrimination against them by the judges."

You could substitute Tri & Blue with Sable Merle and this is exactly what is going on with the Sable Merle in 2008!!! While the prejudice is for the most part in the show ring and not in the whelping box I don't think the sable merle is in any danger of becoming extinct.

The world including "holy" dog standards are ever changing and evolving.