Wow, the water in that stream is green. Is that water very shallow? If yes, it's because it's so shallow that the grass isn't turning to ruined texture. If you're using No Radioactive and More mod, turn ruined on shorelines back on - that should make ruined reappear and make the water look better.

re: the green fertile, I *believe* I changed the fertile from a more yellow to a more green because, after double checking it in real life, I saw that the fertile / farm areas in the Alps are ridiculously green :D. Who knew.