They have partial or Full blue eyes but no other Merle traits
It's called Merle. That's not the name of the dog... Merle is the term used to describe the unique markings of his coat.
The merle pattern is very striking and is fairly unusual. Merle gives a patchy, speckled or scattered appearance which is unevenly place on the coat with no defined pattern. The base colour can be black, brown, red or lighter with the lighter patches created by the merle. A blue merle is a black base colour with blue-grey markings. Some Merle puppies will have Full, partial or even just one Blue Eye.