The green is obtained by adding a small amount of cadmium, but the result is a yellow-green rather than green.
Cadmiunm has health issues so I doubt it's used today.
Here is an article by Ales which you have likely seen which talks about green gold a bit. Most of the pics ar B&W though.
Here a link to an ebay auction selling a vintage green gold watch. It does look yellow though.
Hope this helps,