Not familiar with said song. I can assume it's not meant to be deeply analyzed academically.
I think you're overthinking a cheesy pop song.
And to be honest, I did have to Google the term pleonasm
but I still stand on my assertion that you might be too critical of the songwriter at hand.
Besides, brown skin
in terms of the cultural, political, and ethnic makeup of the US isn't a redundant concept as we still are struggling with racism, minorities, and other related social political issues du jour
is probably just a poetic turn of phrase.