While looking for information about the TV show Car 54, Where Are You, I found black actor/comedian Nipsey Russel was in the cast. His biography says he severed 4 years, was a medic and received a Field Commission. No information on what he did to receive the Commission. Got me wondering about blacks in the WW2 army Commissioned in the field. Did unsuccessful Google search
You can get some general information related to the Pacific here African Americans in WWII | Fredericksburg War Museum
I remembered seeing info about Christopher J. Sturkey, 614th TD Bn, getting a field commission, here's his Silver Star Citation: Second Lieutenant (then Staff Sergeant) CHRlSTOPHER J. STURKEY, 02000693, FA (TD), Tank Destroyer Battalion (Towed), for gallantry in action in Germany on 22 November 1944. Lieutenant STURKEY was helping to direct the movement of 3·inch towed guns across terrain which was heavily pounded by hostile artillery fire. When his comrades left their vehicles and sought cover, Lieutenant STURKEY, perceiving that the valuable pieces of equipment must be immediately moved if they were to escape total destruction, braved the bombardment and, by courageous example, encouraged the men to return to their vehicles and resume the march. By his action, he brought all weapons and men to safety without loss. Lieutenant STURKEY's gallantry and leadership reflect. the highest credit upon himself and the Army. Entered Military Service from Michigan. This was probably pretty rare, I believe black units had mostly white officers in those days. If you can find the book "The Invisible Soldier", by Mary Patrick Motley, Wayne State University, 1975, it contains interviews with black WWII vets about their experiences, Sturkey is included.