I was only able to get one photo of this one.. about 45 feet of water, off Lovango Cay, St John, USVI. My guess is Creole Wrasse, Initial Phase.
Looks like a blue chromis.
I looked and looked in Reef Fish ID.. and never saw that.
I agree with the blue chromis
REEF Headquarters | P.O. Box 370246 | 98300 Overseas Hwy | Key Largo, FL 33037 | USA Phone: 305-852-0030 | Fax: 305-852-0301 | email: firstname.lastname@example.org