I would say no green, but that's not entirely true. I rewrote the auto-green script and so I had to debug it on tonight's puzzle. I will be posting it on my website soon. I will include some instructions on how to make a bookmark of it, so you don't have to cut and paste it into your browser's URL text box every time you use it.
done... ran down one blind alley
very sparse at first, but one you start filling in some greens a lot of pairs show up, which clears the board rapidly. Not sure what makes it "hard" -- I'd call this a medium.
Puzzle is way easier when you don't make a finger error...which takes over 30 minutes to discover. Bad, Bad Finger!!