I do not breed merles or any non-purebred Pembroke Welsh Corgi. If someone tells you a merle Pembroke is 'genetically 100% Pembroke,' they are misleading you. DNA breed markers only go back 3 generations. There are NO purebred merle Pembrokes. Somewhere back in that dog's lines is a Cardigan Welsh Corgi or some other breed that carries merle in order to introduce the merle allele.
I breed to the show standard accepted by AKC in color mutations. While sometimes Pembrokes get blue-eyes and some recessive traits like fluffy, blueie or mis-marks with a high abundance of body white, I don't breed for these traits. Because a number of show-quality dogs carry fluff, fluffies sometimes happen. Please let me know below if you are interested in a fluffy, should one of my breedings produce one (or two!).