There are reasons people might be more comfortable with similar skin tone or genotype... but race does not equal culture
My wife and I are, to a large extent, culturally Texan - genetically, she's of "Japanese" heritage and I'm of "Irish" heritage. We celebrate each other's heritage... but a lot of our connection comes from growing up in the same part of town together.
It makes a lot of sense to marry someone with similar cultural background... but there isn't a 1:1 correlation with race there.