From the release:
The most striking feature of the Kushites is their vermilion and white body paint which they adorned themselves with before battle. Body paint still plays and important part in African tribal cultures. White and red can represent life, death, protection and aggression. Described by Herodotus as the tallest and most beautiful people in the world, they must have been an intimidating opponent.
Cambyeses tried to conquer the Kushites but his army nearly starved to death while travelling in the harsh barren environment between Kushiya and Egypt.
Although never a part of the Persian empire, they did provide regular tribute and soldiers to the Persian army.