Which of the following is not a basic horse coat color?

The choice of Palomino as the answer indicates an understanding of horse color genetics. Bay, chestnut, and black are considered basic coat colors that arise from specific genetic factors.

Bay refers to a horse with a reddish-brown body and black points (mane, tail, and lower legs), resulting from the presence of the agouti gene, which modifies the black coat color. Chestnut is another basic color that encompasses a range of reddish hues and is defined by the absence of black pigment. Black refers to horses with a true black coat, without any brown or reddish tint, which is a distinct genetic trait.

Palomino, however, is not classified as a basic coat color because it is a dilution of chestnut rather than a primary color itself. Palomino horses display a golden coat with a white mane and tail, resulting from the cream gene acting on a chestnut base. This dilution effect makes palomino a derived color rather than a foundational one like bay, chestnut, or black. Understanding these distinctions is key in horse evaluation and genetics.