As part of my oversized 3D set I am printing I am including the Great River. It will just be part of my larger board.These 3D hexes were created using designs by Dakanzla from Thingiverse and printed at 60% oversize. In the pic below you can see the tiles, along with a standard sized Catan hex.
I am keeping the tiles the standard ABS colour with small touches of colour to highlight on them. The only one I am not really happy with is the colour of the wood hex. It was supposed to be a darker green and on the reel looked green, but when it printed it looks very turquise. For this reason I have used more colour than other hexes so I could get the trees green. On the whear and ore hexes I didnt use paint, I used Tamiya weathering powders to create the mottled effect.
(you can click the image to see a larger version.)