I'd love to see these in a mockup of sorts, to see how you want them to be used. As for right now all I'm coming up with is a bit of a palette edit.
Original:
My Edit:
I stretched some of the colors a bit cooler, just due to an almost nighttime vibe the original was giving off. Pushed some colors towards odd ends in hopes that they could be used for other things. At the moment your palette has a lot of brown and a lot of green, so I pushed some towards the reds and purples and grays (to suggest complimentary colors in some cases).
The tall grass in mine changed slightly because it didn't agree with my palette as much, so I made some unnecessary edits. And again these changes were made without knowing how the tiles truly interact, but hopefully some of this helps a bit