Blue Merle Australian Shepherd Coat Colors

The blue merle pattern is a genetic dilution of black (M locus) producing a marbled mix of:

• Blue-gray (dilute black) – base color, silver to slate.
• Black patches – undiluted islands, often on ears, face, saddle.
• White markings – blaze, collar, chest, legs, belly (Irish spotting pattern).
• Tan points – cheeks, eyebrows, legs, vent (if at/at genotype).

Red merle is the same pattern on a liver (brown) base (bb genotype), yielding copper-red marbling with white/tan. Both merles can have blue, brown, or heterochromatic eyes. No two dogs are identical.