A specific term for a reddish-brown horse coat color, similar to sorrel. Used in equestrian or descriptive contexts.
That horse has a beautiful sorrel coat.
栗毛 is a general term for chestnut or bay coat colors, while 柑子栗毛 specifically refers to a lighter, more yellowish-red sorrel shade.
Compound of 柑子 (こうじ, a type of citrus fruit, referring to the yellowish-red color) and 栗毛 (くりげ, chestnut coat color). The exact historical derivation is uncertain, but the term describes a horse coat color resembling the hue of the citrus fruit.