[WIP]Low poly world, texturing ideas?

Hi, me and my partner are working on a game in which we plan to develop the world of australia. We want to make the colors look as realistic as possible according to the real thing though our map is in low poly. Here is what we have so far (just really brief choice of colors to outline/ separate the areas for further texturing):

Do you have any ideas how to blend the colors of the different biomes together so it looks more realistic like in Google Maps here:

Thanks all! Would much appreciate the feedback and suggestions.

P.s. Currently just using diffuse material

The first thing you can do is have textured blending of the biomes based on the height data (like different coloration on the mountain ranges).

Also, this applies to blending in general, biome regions will not always be divided neatly on straight lines.

Hi thanks for the reply, what kind of method would you approach with to going around doing that?