Heya, I had a problem with GPP, causing gas giants to have a thick white atmosphere;
So I made a clean build of KSP and thanks to a lucky guess, I found out that Scatterer is the cause, so I played around with the configs and repaired it to this state:
Which, however, made red Gael-like sunsets on each one
If anyone is interested in the configs (GameData\GPP\GPP_Scatterer\Planets\[Planet Name]\atmo.cfg):
Nero:
Gauss:
Otho:
(The effects were mainly by cloudColorMultiplier, cloudScatteringMultiplier and cloudSkyIrradianceMultiplier)
KSP v1.2.2.1622
GPP v1.2.3
Scatterer v0.0300