Up until the Korean War the military was segregated.
Almost all combat troops were Caucasians, minorities served in support roles (which could be just as dangerous for them as front line troops). So it should not be a surprise that a WWII mural would not have too many if any minorities portrayed.
Then reality is not very strong in the snowflake generation.
You posted “Up until the Korean War the military was segregated.”
Let me add to the discussion: The military was “officially” desegregated per President Truman’s Executive Order 9981: Desegregation of the Armed Forces (1948).
However the Army got around it by moving segregated black battalions into white regiments but leaving that battalion as entirely black. For separate battalions, it was done by a similar swap out of one white company for one black one, leaving the battalion with 2 white and 1 black company.
It was only with the need for replacements, especially in the infantry units, that true integration was attained. The personnel replacement system could not maintain the “pretend integration” that had been done between 1948 and when the Korean War began. I cannot comment on how the Navy and Air Force complied with Truman’s EO.