"Ground textures are usually surprisingly dark, and only bright in a photo because of the choice of exposure."
This is exactly what I've been thinking especially after taking photos but there is a tendency to make lighter ground surfaces in TG2. This is what happens in Mojo a well.
I do believe TG2 defaults are quite like conditions in the UK.
So the exposure in the camera settings is the same as sunlight strength but camera specific so we can have various cameras exposed differently instead of having to adjust the sunlight. I've never really adjusted the camera exposure.
Then the route to experiment with is simply surface colours in relation to sun strength (or exposure) and atmospheric/cloud tweaks. When I brought the sun strength up I had to adjust the clouds and atmosphere but I was happier with the results from that planet.
