Help please - "factoring" questions

Sounds like dad could be a tri, or maybe even tri factored..
Now heres the simple break down.
Tri Factored, means they carry the gene that when bred they can offspring a tri dog depending on what they are bred to.
White Factor means they carry the gene for white factoring, (think lots of white) but not always..it is different from the irish factor which gives full white collar and legs...Usually breeders can quickly look at a dog and the wives tale is white up the inside of the leg=white factored...not always true and some times you dont know a dog is white factored until you do a breeding and you end up with some color headed whites and go hey, mom and dad must be white factored for that to pop up.
Sable Merle is from breeding a sable with a Merle. It dilutes out the sable and sometimes mottles it or you get that washed out sable color and some times blue eyes.

Now with all this said...variations, anomalies etc can happen...percentages etc play into what happens with each breeding.

 

Damn! You're good, Linda!

 

So Shelties only come in two colors, black and brown (colors, NOT patterns).

If Dad is brown and Mom is black (a blue merle is just a diluted black), then the puppy must get a black gene from mom, because that's all she has to offer. Because the puppy is brown, you know he got the brown gene from Dad, because if he got a black gene from dad, he'd be black.

ALL the puppies in the litter are black-factored because their mother is black, it's dad that decides whether they are black or brown by what he passes.

Then add the merle gene to whatever color they are, and there you go!

 

I think the important thing for you is to know that merle dilutes black better than it dilutes brown. So as the puppy gets older and gets darker, the merling will be much more apparent.