What is a black shoe?

You may wonder what Black Shoe is about.
I was commissioned an Ensign in the Regular Navy, USN December 22, 1971 in Albuquerque New Mexico. Uniform of the Day was Navy Dress Blues. I had at that time been promoted to Electronics Technician Second Class (ETN2, or E-5) with designation of (3324-SU, for Ships Inertial Navigation Technician Submarine Unqualified). I was given the choice of commissioning via either NESEP (Navy Enlisted Scientific Education Program), NAPS (Naval Academy Prep School) or continue enlisted with duty going next to New London Connecticut. I had chosen NESEP and spent the following 40 months in Albuquerque at the University of New Mexico, UNM.
In those times there were two officer groups referred to; black shoes and brown shoes.
It was in the Zumwalt era, Adm Zumwalt was the Chief of Naval Operations July 1970 until 1 July 1974 Black Shoe Navy referred to the Surface Navy Forces, while Brown Shoe Navy referred to the Navy Aviation Forces.
Black shoe seemed a misnomer, since surface officer summer uniform was khaki colored with a brown belt and wore brown shoes, sometimes referred to as the Buster Brown uniform. Aviators on the other hand had a similar belted blouse top in dark green. Every USN officer had three dress Class 'A' uniforms, Blues, Whites and either Surface Officer's Khaki or Naval Aviator's Greens.
The last version of the belted Greens I saw was on a blimp pilot in 1974.
I loved being in the Khaki belted blouse uniform for its trim professional look.
The White Class 'A' uniform was sometimes referred to as the Good Humor uniform, perhaps a reference to the ice cream company of that name. I believe my wife fell for the Dress White uniform.