Racism did exist in the armed forces; it was part of the background of society at the time, though it probably wasn’t malevolent. I know my uncles, who were all vets (Army Ranger, Merchant Marine, and two Army Air Force), had attitudes running that way when I talked to them after the war. It wasn’t intentional; no one knew different then.
"It was a different time, you understand." - Wallace "Suitcase" Jefferson