You have given / found the the answer yourself to your question .
Yes; it is green or green with yellow stripe is normally used for the ground /earth connection conventionally for connection to the AC equipment earth.
But, for connecting work surface to the common ground point normally the grounding cords are used with snap buttons which are offered in black as well as green colors by many suppliers.
Good morning /afternoon from India Mr. SR.
I suggest you to please go ahead with what you are using and record it in the document if documentation is required and if you are maintaining or retaining for ISO purpose. .