Spock was to be red.
The famous Spock, known for his characteristic eyebrow, lack of emotion, and well-known hand gesture, was to have a very different look from the one we know. The creator of Star Trek suggested that apart from the pointed ears, he should have had a reddish skin color to give him more of an unnatural look.
Of course, this hand gesture means "read between the lines"...
He came up with it for the character. He's the reason it's in the show. That's all that anyone needs to know. Pointy ears weren't a new thing, either.