Welcome back to Canada, where we've been shooting propane/green in stock Marui pistols since like 2004.
No, we're not being foreigners about it, either. This site will help you:
http://www.airsoft-innovations.com/
Edit: Cuuuuuuurse you Hadeeeeeeeees!
Caveat, green is ok for stock Marui gas blowbacks, as well as some other brands. It's generally not recommended for most non-blowbacks and certain brands.