Merle (coat colour in dogs) Jump to: navigation, search Blue Merle Border Collie puppy Merle (In Welsh:Brych) is a colour combination in dogs’ coats. It is a solid base color (usually red/brown or black) with lighter blue/gray or reddish patches, which gives a mottled or uneven speckled effect. Although most breeds that can have merle coats also typically have white