Thanks to Mawerick from Rising Phoenix, you can use the following temporary solution:
Use this command when entering a dark dungeon, static of mission (any indoors playfield):
/fxscript Tweak_Rubi-Ka_Sunlight #
For a convenient macro:
/macro Light /fxscript Tweak_Rubi-Ka_Sunlight #
This will get reset when you zone, so you need to do it whenever you zone into a dark place.