The inhabitants of Cheron were an extremely long-lived race (one was reputed to have pursued a criminal of his people across the Milky Way Galaxy for over 50,000 years). They possessed extremely fast space ships with an advanced cloaking technology, and also possessed advanced protective shielding systems on their persons, which could also be utilized to disrupt sensitive computer systems and as weapons against others. Some members of the species could also command advanced technological systems by sheer willpower alone, bringing vessels as large as a starship entirely under their control to send where they pleased.
Inhabitants of this planet bore a peculiar physical appearance: their skin was exactly half-black and half-white, with some white on the right side and black on the left, and others the opposite. Those who were "black on the right side" considered those "white on the right side" to be inferior. They subjugated their brethren in what they thought was a gesture of mercy and compassion, but the "whites on the right side" considered it nothing but slavery and oppression. By 2268, civil war had completely destroyed their civilization, leaving only two known survivors, Bele and Lokai.
Bele referred to Lokai as "half-white" in a tone clearly meant to disparage; Lokai referred to Bele as "half-black" in a similar fashion. From Bele's reaction to Kirk's suggestion that his people were once of one color, and both aliens' use of phrases such as "monocolored trash" it may be assumed they regarded their own dual colored lifeforms as superior to singly colored lifeforms. (TOS: "Let That Be Your Last Battlefield")