Well just because you were thinking about COLORS (There is even a Purple Grass!) and a bunch of all kinds of colors like various greens. Dirt and mud too... All forms of "brown" colors. Seeing it in this form may be more helpful.
Another option is to see what Warhammer 40,000 Players use. They sell miniatures for the various units. Some people paint them... Others do this as a JOB: painting miniatures!
Anyways maybe this LINK is more relevant to you:
https://www.yeggi.com/q/warhammer+40k+terrain/
Although they may not have what you are LOOKING for... Again just for inspiration or give you ideas. If you plan on 3D you will need to produce STL file (Why? Because we did Starship Models for TradeWorlds and we needed the STL files to send to the Manufacturer).
Again this may (or may not) help. Just sharing some bookmarks that I've had for years now ... Once I find them.
So far:
3D printing would get me simple colours. But I would use hexagons, triangles on top or even other objects that remain flat yet are added with help of a peg.
Even mountains would remain flat... We need to be able to place air units you know.
Using cardboard. I would simply use "ridges" again. But then the main hexagons would be pure.
And mixes would simply be several levels.
Grass, grass with a tree, grass with several tree's and finally a forest.
The "ridge" or connecting part of the board. Would then be half forest and half grass in all cases where one hexagon would be completely forest.
Doing this from scratch again...
But the start would be:
Barren
Either barren hexagons with rocks as objects.
Or barren, barren with a rock, barren with several rocks, entirely rocks. And of course "ridges" with barren going into rocks.
so, in your oppinion, what would be better?
"3D" printed or cardboard?
Either way, I have gotten to a point. Where I would love to see maps ranging from 2 hexagons to infinite hexagons. Just like the good old days.
Having a square or rectangle map filled with hexagons is a no go at this point...