The Rainbows Contained in Your Skin and Bones

Humans carried the mark of their soulmate's first touch etched into their skin. A pitch black mark that would turn to rainbow when touched by their soulmate.

Vulcans did not have soulmates or soulmarks. And Spock, even with his human half, took after them and did not have a soulmark. This, of course, meant he did not have a soulmate, despite desperately wanting one, right?