Just to clarify: I didn't change the old ones - I did all the new ones from scratch. But I tried to keep the general look of most zones - apparently that worked well enough.

I guess to really see the changes, one has to see them in the game again, not just on screenshot. Especially when you have opened two simutrans windows parallel (with the same map but with different versions of that pak file) the differences are clearly visible.
Just wondering if should do that again via SVN or just put the pak here?
But yes, a brighter desert (actually it's now a sandy desert. I know that not all deserts are of that type - far from it! - but I think that's what everyone has in mind when talking about deserts anyway), and less grainy textures were two of the main objectives. Also I wanted tropic, mediterran and temperate to be more easily distinguishable from each other.
Ok here is what I got so far:
(please backup your original
ground.ClimateTexture.pak and
ground.LightTexture.pak)
Remember: this is still just a prototype, not the final product - so nothing is fixed yet.
EDIT: file removed - new textures are part of the pak128 nightlies by now