Green may mean that it is good for the environment (the most frequent usage I am aware of), or as a label for something that someone hopes will be perceived to be good for the environment (eg. green washing by corporations). I am not familiar with it being specifically used to refer to something politically correct (although someone could easily claim this for anything that is widely accepted as an ethical norm.). Once again, with regards to a political agenda, any issue can be used as part of a political agenda. Without further information, if someone said that something was green, I would assume it was supposed to be good for the environment…whether or not it is, is another question. Or, that it wasn’t red