Note 6 — Chapter III · Rise and Prosperity of Sulu
Reading edition
This color distinction is difficult to explain, but it must have arisen out of the established custom of dividing slaves and captives, after returning from a piratical expedition, among the great chiefs of the various parties which composed the expedition. These parties as a rule belonged to four sections representing the four great districts of the island, over each of which one chief formerly was in authority.6