The term 'Horse of Colors' is a reference to the roan horse, which is a horse with a coat that has intermingled white and colored hairs. Roan is a four-letter word that is often used in crosswords. The roan horse is a popular breed of horse due to its unique coloring, which can range from a light reddish-brown to a deep black. Roan horses are also known for their strength and agility, making them a popular choice for riding and racing.