i don't think 2 light-skinned people together is as unusual as we think in our heads. and 2 dark-skinned people together is typical and unremarkable.

i know a couple who could both pass for white (seriously -- i met them out one time and overlooked them in the restaurant a few times cuz i thought they were white people), i know a real light-skinned sister married to a white dude, a real light-skinned dude married to a white woman -- and in all 3 cases their kids look straight-up white -- and i know more than a few high yellow couples and high yellow-caramel pairings.

back in the day i think it was more "transgressive" for light-skinned women to date/marry dark-skinned men, but now that it's really not, people just go off personal preference, and personal preference will either be for the same, or for opposites attract.

sidenote: are jay-z & beyonce a "light-skinned" couple? i'm not sure if jay is light-skinned or not