What is a distinctive feature of a chestnut horse’s body coloration?

A chestnut horse is characterized by a body coloration that can exhibit a spectrum of shades, ranging from a bright orange to a deep red-brown. This broad variation in hue is what distinguishes chestnut horses from other colorations in the equine world. The term "chestnut" itself encompasses a variety of shades, which can include lighter tones like sorrel (a lighter reddish color) all the way to darker, richer red-brown colors.

The other options do not accurately describe chestnut horses. Pure black coloration is representative of a different coat color entirely. Black points, which refer to the darker markings found on certain breeds (like on a bay horse), are not a feature of chestnut horses, as they typically do not have such markings. Additionally, the idea of a golden shade is more aligned with the palomino coloration rather than chestnut. Thus, the wide range of coloration from orange to deep red-brown is indeed the definitive characteristic of a chestnut horse's body coloration.