This is one of my custom pp filters, hope it comes in handy for some of you. My in game saturation level is set to 100.
evened out the auto exposure, done away with the ring round the sun lightened the god rays a little and also reduced the saturation so the colours are not so vivid.
Just drop in your filters folder in documents/assetto corsa/cfg/filters
and also in program files (x86)/steam/steamapps/assettocorsa/cfg/filters.