One of the features of the Australian Shepherd is the richness and variety of its colouration and markings. The Aussie comes in a variety of body colours; each Aussie’s markings are as individual as the dog itself.
Blacks, reds, and merles
The basic body colours of Australian Shepherds are black or red, with red being the result of a recessive gene. These colours may appear with or without white trim and with or without copper points. A predominantly black Aussie with white trim and copper accents is called a black tri; substitute red for the black, and you have a red tri. A black dog with white trim and no copper is called a black bi, and a similar red is called a red bi.
The two other accepted colours are blue merle and red merle. The merle gene (which is dominant) breaks up the predominant colour (black or red) into a pattern of black patches on grey, or in the case of a red, red patches on silver to buff. Merles can also appear with or without white and copper trim.
All black and blue merle dogs have black noses, eye rims, and lips. All red and red merle dogs have liver or brown noses, eye rims, and lips.
The following colours are considered disqualifying faults by the ASCA and CKC Breed Standard: sable, brown merle, brindle, gray/slate, diluted red, and blonde. Other colour-related disqualifying faults include white body splashes and white surrounding the eyes.
Range of body colour
Additional variety can found in the basic body colouring. All colours should be clear and rich, but the red may be such a deep mahogany that it appears dark brown, or it may be a lighter shade. The copper trim colour may be pale, like latte, or it may be a dark, rich tan. Merling may be heavy, so that solid patches are few and small, like leopard spots; or it may be light or minimal, so that the dog has large areas of solid colour. The result is that no two Aussies are alike.
Eye pigment patterns in the Aussie can also be varied and unusual compared to that of other breeds. A black Aussie will in most cases have brown eyes, though blue eyes do sometimes occur, or even a single blue eye. Brown eyes may range from a dark brown to golden or even yellow. A dog may even have two brown eyes of different shades. A red Aussie may have brown or amber eyes, or sometimes blue or green eyes. For black and red Aussies, blue eyes are determined by a recessive gene independently of the merle gene.
The merle gene also affects eye colour in that it removes pigment from most or some of the iris. As a result, one or both eyes may be blue, or have specks of blue, or even be marbled or split with blue.
Whatever the variation in body or eye colour, no single colour or pattern of markings is considered more attractive, desirable, or acceptable than another. Taken together, colour variations are part of what makes the Aussie so interesting.
The website http://www.ashgi.org/color/index.htm contains a wealth of information and photographs concerning typical and unusual colours of the Australian Shepherd, as well as information about the inheritance of colour.