I have a feeling I'll be replacing alot of plants this spring because of the winter damage. Might as well get new and different ones! I just put this one on my wish list!
Check out the first page of this topic, there are links to Green Coneflower, Green Zinnia and a Green Rose.
I once grew a small nicotiana plant that had green flowers. I believe the word bell was somewhere in the name...It reseeded one year, but the next didn't come back again...I'm going to go look it up. nicotiana langsdorffii I think that is it, although it is large and not small...I might have grown something else.