It won't stay green. Most of the suggestions on that website will fade over a month or two some earlier than that. It's a waste of time and money. There are a few lists on this forum of stable natural colourants.
Mine is really odd too. It morphs into this gross Army color and then sometimes goes back/sometimes stays. I've gotten morphed and original color on the same bar.Green Vibrance from Nurture turns an ugly gold and does not morph back for me :-(