Yes they can be mahogany sable merles or CHW.
The sable ,white factoring and merle are all seperate.
So in a nut shell chose one in each area.
1. Sable or Black(if black, tan points or no tan points)
2. Merle or not merle
3. Non White factored, White factored or CHW
Most Sable merles are Tri or bi factored as they result from blue to sable breedings. The black gene from the blue ,sable from the sable. So in theory they shoud be dark sables were the merling gene has not produced dilution just like the black is still black in blues. But this is not the case always. Pike is actually a tri factored white factored sable merle. He was very merled when he was born. No doubt in anyones mind that he was merle. But as he got older the merling became less obvious so that most people can't tell. Ember's brother and sister were just as obvious when they were born. They are darker over their backs then Pike as adults but the dark shaded sable just looks mottled. Below is a picture of Ember's sister.
I think they call Duncan's color red sable. You see it in some lines not a common color. I think I read in Shelties in America that the color goes back to a dog called Kim O'Page's Hill, the first sheltie seen in that color. Diva has a half brother that color.
Thanks! Abbie is definitely quite dark, even to the point of black tips.
And Duncan is a direct descendant of Am Ch Kim O'Page's Hill and Kim's full sister Pandora O'Page's Hill as well as a slew of other mentions. Very cool to know that the coloring came all of the way down! Duncan's sable full brother is the exact shade of Duncan.
Here's a picture from back in March when we had a little Puppy Reunion with the only boys in the litter of six. Duncan on our left and his brother on our right. There was a 10 lb difference then. I can only imagine now!
http://i800.photobucket.com/albums/yy282/the_gallows/Random/DSC_0031.jpg


