I had an issue with the planet Gravesworld. This is a screencap of the planet - http://en.memory-alpha.org/wiki/File:Gravesworld.jpg
. When I see this image, I imagine a person focusing a flashlight beam on a globe. It looks unreal, and is very noticeable in the episode.
Looks fine to me. The planet has kind of a glowy, magical feel to it, which I think was probably the intent.