My question was basically just one of color. You see, I'm a gene major and i don't understand how you can possibly get merle pups all of the time without breeding double merles.
You're speaking of Toolalla Coolies - they (mainly Tabitha Parker) LIE and say they never produce double merles and never produce solids. I used to be on her dog forum and when another member asked me the very same question that you did --- I answered and it made Tabitha so mad because she was caught in a lie that she banned me from her forum and has spent the last year trying to discredit me and my dogs.
I'm inolved with shelties and know that double merles are usually highly frowned upon as many times they have semi-lethal effects.
Coolie breeders do practice breeding merle to merle (M/m to M/m). Most are of the understanding and through mis-information, that the Coolie breed is an entirely merle breed. Which is genetically not possible. Trying to explain that to those breeders was and still is like banging your head against a brick wall. Merle to merle breeding is accepted among that community -- and there are those that still wonder why in the world they produce puppies that are blind, deaf, or both.
I know that double merle x solid can create a 100% merle litter, but if you breed a merle x merle then you get a 50% merle, 25% double merle and 25% solid litter.
It doesn't work like that, in real life situations. Although every single breeding is different - usually Merle to merle produces mostly merles, if not all merles. Some produce 1 merle, the rest solid. Some produce mostly merles, 1 or 2 solids and 1 or 2 double merles. Toolalla kills all solids at birth. They usually kill the doubles, but not always. Most breeders do not kill the solids; and some breeders still have NO clue why they produce solids. I've tried to explain, but it goes smoothly over their head.
Is double merle not as much of a concern to Coolie breeders in general?
Toolalla doesn't care, as evidenced by their continual practice of only breeding merle to merle. It worries some of the other breeders, but they still breed merle to merle. I have to admit some of these breeders are the luckiest in the world at not producing double merles, with their continual practice of merle to merle breeding. Those ethical breeders do openly admit what they produce and make no excuses, they also take responsibility for what they produce (for the life of the dog). Toolalla/Tabitha Parker does not admit they produce doubles or solids.
And why in a working breed is color so important to the breeders?
Tabitha/Toolalla has said that every single puppy that they've ever produced (she said they've beed breeding since the late 40's early 50's) turns out to be a working/herding dog. Well, if that is so then they have genetic anomalies whose genetic makeup would benefit the entire herding world. 
Some don't care what color the dog is, as long as he/she works. BUT, most Coolie breeders do try to produce the merles. It's all from mis-information. They were told, have been told and continue to be told that the Coolie is an entire merle breed. This is the most idiotic thing I've ever heard. It's not genetically possible, but some won't listen, some don't care, and it's like banging my head. Toolalla is the leading force in saying the Coolie is an entirely merle breed and that solids are throw-backs (which she has never defined what exactly these "throw-backs are, or what breed). Which is NOT true, but Tabitha Parker will not listen, so it's no use --- they will continue to breed merle to merle and kill puppies.
To me color seems like the last thing a working dog breeder should be worrying about especially when dealing with a gene so dangerous as the merle gene.
Breeding self merle to self merle is better than breeding two merles that are irish spotted, pie bald or extreme pie bald. Some of the Coolie breeders are going to continue breeding merle to merle no matter what they are told. It's better to educate them as to what is safer, than to flame or argue with them. Of course, there are those breeders that won't listen no matter what.
I currently have several cryptic merles; I know they are cryptic, because they were merle at birth, and as they've gotten older their merling has faded (due to being sable in color). Two females that were imported from Australia were said to be a solid color, but when I bred them to a merle --- I knew INSTANTLY they were cryptic. I do not practice breeding merle to merle, because I do not like killing puppies. Accidental merle to merle breedings do happen and if anyone says they've never had an accidental breeding, is just not being honest. No matter how careful you are, if they aren't desexed, accidents can happen.
