Failed to load mods: custom-map-colors/code/entities-and-paths.lua:68: attempt to index field '?' (a nil value)
stack traceback:
custom-map-colors/code/entities-and-paths.lua:68: in main chunk
[C]: in function 'require'
custom-map-colors/data-updates.lua:1: in main chunk

I see the same issue when switching off SA mod.

I'm getting a similar crash, with the only difference I see being the underscores around the mod name.

Failed to load mods: custom-map-colors/code/entities-and-paths.lua:68: attempt to index field '?' (a nil value)
stack traceback:
custom-map-colors/code/entities-and-paths.lua:68: in main chunk
[C]: in function 'require'
custom-map-colors/data-updates.lua:1: in main chunk

Mod currently requires space exploration to work...
If you disable space exploration, it gives these errors

I'm really sad that I never noticed this mod was broken in vanilla, since the fix was seemingly fairly simple, but I only ever played it with Space Age since 2.0 released.

Here's a custom v0.7.8 with additional checks in place to ensure things exist before attempting to modify them, preventing the errors.

I'm not entirely sure if it's actually working correctly, since I don't remember what color the cliffs are supposed to be changed to, but it loads and changes the other colors, so I can only assume it's working.