Stable color is a term used to describe the color of a horse's coat that does not change over time. The crossword solution for stable color is 'roan', which is a coat color of a horse characterized by an even mixture of white and dark hairs on the body, while the mane, tail, and legs are usually darker than the body coat. Roan horses can be any base color, from bay to chestnut, and the roaning pattern is consistent throughout the horse's life.