Active or Passive
The beach is active yet it is away from the plate boundary and closer to the inside of the pacific plate. The reason it is so active yet inside the plate is because it's a "hot spot" or over a mantle plume.
Primary and Secondary
It is combination coast. It was a cinder cone volcano that collapsed in on its self and now the ocean slowly erodes the beach and cliffs away naturally.
Submergent and Emergent
It was emergent in its creation because it rose from the bottom of the ocean as a volcano but now it is submergent as the ocean washes away the shoreline.
The sand is green due to olivine, a silicate mineral containing iron and magnesium, and will continue to be green for many years but will eventually deplete and the sand will look like any other normal beach.