In this case, I think two things play a role.
- chromatic aberration:
You can recognize it very well in the lower part of the picture where the intense light is reflected by the snow.
This can be partially corrected with the chromatic aberration module by switching on “very large chromatic aberration”, increasing strength and using “darken only” in this case:
- Out of gamut blue in highlights caused by LED lamps.
If you are using Filmic, you can move the highlights saturation mix slider to the left in the look tab to desaturate highlights…
…and then also play with gamut compression and saturation of the blue channel in the color calibration module:
The whole thing is much easier with the Sigmoid module. You just take the “smooth” preset and increase a little blue attenuation slider to desaturate blue in highlights:
In addition, you can also use the rgb primaries module to move the blue channel to cyan and the red channel to yellow, which completely eliminates purple fringing:
