Moosmom - Blue merle is a coat pattern. Black patches on a grey/blue background. There can also be red merle, and a dilute form of both colors. It is usually accompanied by rust colored and white markings on the legs and face. Merle can be found in many breeds. Here are some pictures.

Blue Merle Cardigan Corgi


Blue Merle Sheltie


Red Merle Australian Shepherd


Red and Blue Merle Cardigan Corgis



Dilute Blue Merle Australian Shepherd