For those who do not want to mess around with the gamma settings again and again and again ...
There are graphic card tweakng tools. For example, if you have an nVidia card, the \"RivaTuner\" (besides many others). RivaTuner can be loaded while booting and resides in the tray.
You can save a preset with tweaked gamma settings. Then you can add a preset for the included \"Launcher\" inside RivaTuner, assign the Gamma preset to it, and the application \"psclient.exe\". (Other tools may work differently, but similar.)
Then you can launch PlaneShift from the System Tray Icon of RivaTuner by right-clicking on it. RivaTuner will first apply the gamma settings, then start PlaneShift, wait for its exit, and restore the gamma settings afterwards.
From my experience, a gamma factor of 1.7 shall be sufficient as start for own experiments.