Olive & Drab Green Sea Glass
There are so many different colors of green sea glass. Some is true green, the variations go each way on the color wheel - to the blue greens and the yellow greens.
Olive green is common to rare in Puerto Rico depending on the shade of olive green. Olive green sea glass that is so dark that you can only see the color by holding ot to the light is from "black glass" and that is ultra rare.
Olive green sea glass in Puerto Rico is found in various shades. It comes from liquor and wine bottles and I can think of no other source. Scotch bottles are one of the main culprits.