Yersinia79:That is most likely caused by the assigned emittance to those effects, emittance uses weathers to have a dynamic range of different RGB colors based on the time of day.
Emittance time cycle types;
Normal region weathers such as Pine Forest - SkyrimClear, SkyrimCloudy, SkyrimFog etc
FXWeatherSunlight - Only has RGB values to affect the emittance and nothing else, except for the Sun glare and Moon glare for some reason with a 255 RGB value.
FXWeatherInvertDayNight - The way it was meant to work was to assign the RGB values of the nights to the days and vice versa so it would have Night emitting lights during days. But the RGB values was poorly assigned by Bethesda. It was either sunset or sunrise that had a black/0 RGB value to it

Then there are other similar FXWeathers with different RGB values assigned to them.
The emittance can be assigned to static, light bulbs, FX effects such as "candle" glow and dust/sun beams.