I remember in the ‘60s there was a controversy about that. He was a white “passing” for black for the political position. Even the Wiki on him states when young he had blonde hair and blue eyes...
As a born & bred New Yorker, I remember him well and the 1960s even better. Wiki is often wrong, so I don't know if he was a blonde baby or not, as he was much older than I; however,he never had blonde hair during my lifetime.
FYI.....many blacks/mulattoes have blue or green eyes; Derek Jeter for one.