I am getting the following very unpleasant visual effect from a party picture I am trying to post-process in RawTherapee. Basically, I would like to have the regions where the lights pointed to look white and white-ish (as they actually were in real life) — and not light-purple and dark-blue.
The picture was shot with my Nikon D750, and the camera (somehow) managed to fix this in the JPG it exported alongside the raw file.
I have tried to debug this, and it seems that for those specific pixels the red and blue channels are saturated (or almost saturated) whereas the green channel is completely unsaturated — any ideas why?
I thought I might be able to deal with this by adjusting the tint accordingly (for purple to green). That worked as expected for the highlights, but ruined the rest of my picture.
I believe the issue could be solved by having the red and blue channels "bleed" into the green channel when they approach saturation. But I found no way to do this in RawTherapee. Do you know how/whether this is possible?
Maybe I am having his issue because RawTherapee has no colour profile for my camera yet (I am thinking maybe it is normal for the sensor to just cut out the green for very strong colours). Any ideas how I could best get a colour profile?