"... racked my brain to wonder why I foreclosed any possibility of them being black."

Not sure either, Brother, cuz they've seen US as the proverbial, front-line "cannon fodder" in every war in which they decided to allow us to participate since Truman (white supremacist that he was, and needing the Black vote for reelection) desegregated the armed forces with Exective Order 9981 in 1948.