@anon41087856 It’s not necessarily just the red channel coefficient. Here’s another image from the same camera with red = 2,672 when the wb is set to camera reference. But applying the color calibration does not give a cyan hue to the white patch.
_DSC3684.ARW (47.1 MB)
_DSC3684.ARW.xmp (18.1 KB)
Again, image is not mine and exact source is unknown.