I used the ColorMix shading app to add shading to the original model of lunar surface. I think it really adds depth to the terrain.

Learn more about Prusa ColorMix in the blog article.
To correctly open the 3MF project file (which includes virtual extruders), make sure to use PrusaSlicer 2.9.6 beta (or newer), which introduced support for color mixing. In older PrusaSlicer versions, the model would instead only use normal extruders.
I printed the model on Prusa XL, with 0.15mm layer height. Printing at 0.10mm will achieve even better color shading. I used Prusament PLA Marble Grey and Galaxy Black.
Make sure to print the model standing up with a brim, as in the sample pictures! The shading won't work in horizontal orientation!
The author remixed this model.
Added MMU color painting.