The phrase "solid liver" refers to a type of color or pattern found in animals, especially dogs and horses. It means that the fur or coat is entirely dark brown, without any spots, stripes, or other markings. Full definition
The breed's flat to moderately curly coat might be any color from solid liver to solid chocolate, with perhaps a white spot on the chest. (wildfowlmag.com)
It comes in solid liver or a combination of liver and white, liver patched and white ticked, or liver roan. (puppy-training-solutions.com)
Coat colors include solid black or solid liver with feathering along the chest, legs, and tail. (dogingtonpost.com)