A great place to look for green wine glasses would be amazon. Check out the amazon website and do a search for green wine glasses. They have so many products you just may find what you're looking for. You can also do a google search.
One of the most likely places would be Pier One; they carry a wide variety of unique glasses. You might also try Williams and Sonoma, though they will be more expensive.
Any decorative store like Pier One, Bed Bath and Beyond, or even Sears, Ross, or Target might have green wine glasses. If you can't find glasses at these stores, there are various online outlets to shop from.
You can call your neighborhood Target or Wal-Mart to verify if they carry green wine glasses. They do carry wine glasses but depending on the marketing area it would be wise to call before making a blank trip. Also calling your favorite winery will give you help or suggestions who sells green wine glasses.