In the Alundaio's OpenXRay source I found two types of weather presets:
1) in configs/environment/weathers/ eg. default_clear.ltx has definition of clouds_color consisting of 4 floats (first 3 are always 0, last is transparency)
-- I found that AF1.3 uses this format but clouds_color.rgb is set to zeros
2) in configs/weathers/ eg. weather_default.ltx clouds_color is defined as 5 floats (each are changing between different gametimes)
Which presets are used by the game?