He is indeed an Obama appointee.
Promoted by Trump to his current 2 star rank:
Special Operations Command South’s Commander U.S. Navy Rear Adm. Collin P. Green was promoted to the rank of rear admiral (upper half) during a ceremony Dec. 1, 2017, at Homestead Air Reserve Base, Florida.
The promotion comes after Defense Secretary Jim Mattis in March announced that the president had nominated Green, a U.S. Navy SEAL and a Bowie, Maryland native, for appointment to the rank.