If you grab patch 0.4.4.1 you’ll see in the launcher dialog a new graphic setting quality option called “custom [debug]”. Select it.
In the mean time, go on your hard drive where the game got installed and edit ClientConfig.xml ( ex.: C:\Program Files\I-Novae Studios\Battlescape\Dev\ClientConfig.xml ). Make sure you keep a backup copy of the file, and make sure you edit the file with administrative privileges, otherwise your changes might get ignored by the system ( verify the file date has changed after you modified it ). It’ll be fine if you installed the game on a custom drive, but in the default C:\Program Files, you need admin rights to edit files.
At the bottom of ClientConfig.xml you’ll see a bunch of quality settings:
Ignore AntiAliasing quality ( keep it to 1 no matter what, higher values are for experimental temporal AA which isn’t working yet ).
The values range from 0 to 3, 0 being for lowest and 3 for extreme. As you can see you can change the parameters independently for each category, whereas in the launcher dialog it overrides all these values and uses the same value for everything.
Since the problem seems to happen in “Extreme” mode, the idea is to change these categories to 3 one by one. Only do one change at a time, test the game, and see which one is causing the blue-filter glitch.
There is a good chance it’ll be related to LightingQuality, but it has to be confirmed.
Let me know the results once you do the tests, thanks !