Anyone remember this classic Star Trek episode?

Let That Be Your Last Battlefield

"The Federation starship Enterprise is on a mission to help decontaminate the polluted atmosphere of the planet Ariannus, when sensors detect a Federation shuttlecraft that was reported stolen. The craft is brought aboard along with its alien pilot, who identifies himself as Lokai, a political refugee from the planet Cheron. Lokai's most striking feature is that his skin is ink-black on one side of his body and chalk-white on the other side.

Shortly thereafter, sensors detect another spacecraft in pursuit of the Enterprise. The alien craft disintegrates, but not before its pilot, Bele, transports to the Enterprise bridge. He is colored black and white, similar to Lokai."

"As Bele continues angrily to press his matter with Starfleet, he reveals the source of his conflict with Lokai. He, and all of his people on Cheron, are black on their right sides, while Lokai's people are all white on their right sides. The distinction is lost on the ship's officers..."

https://en.wikipedia.org/wiki/Let_That_Be_Your_Last_Battlefield