I'm not entirely sure as it could be about many things. It might be a story where love is explored in the context of nature (since green is often associated with nature), perhaps with characters falling in love in a forest or a garden setting.
Well, first, check the major fanfiction platforms. Some of them have really good search functions. Archive of Our Own is known for having a wide variety of fanfictions, so it's a great place to start. Also, FanFiction.net has a large collection. Another option could be Wattpad, although it has a broader range of content including original stories, but it might still have the 'love in shades of green fanfiction' you're looking for. You might also want to check any relevant fandom - specific forums or communities where fans might share or recommend such fanfictions.
I'm not entirely sure specifically about '50 shades of green fanfiction' as it's not a widely known mainstream concept. It could potentially be a fan - created story inspired by the '50 Shades' franchise but with a 'green' theme, perhaps related to environmental ideas or a character named Green in some way.
The fanfiction of Fifty Shades of Love can be interesting because it allows fans to put their own spin on the story. For example, they might change the personality traits of the main characters slightly to see how it affects the relationship. It also gives a chance to explore different time periods or scenarios for the characters. Maybe in one fanfiction, the characters are in a different country or facing a different social situation, which all adds to the richness of the story.