Clouds can look pure white if the screen isn’t entirely filled up with sky and the sun’s bloom is excessive. Running a HDR 60O monitor with the latest game ready drivers.
I am finding the same thing and have reverted to running non HDR in game. I have a HDR400 monitor and the clouds are very blown out with it enabled. I wish there was a calibration slider to control the paper white value and max brightness like other HDR titles.
Very bright on my screen too. Tried changing television settings and Windows 10 HDR settings. Still too bright during the day, then so dark at night that I can not see my plane.