Need to keep in mind here that the camera doing the capture of the negative is not trying to align scene colors, it’s trying to align the negative colors. The film recorded the scene colors, long ago…
My inversion is four steps:
- Set black and white points for the red channel to the red data min/max
- Set black and white points for the green channel to the green data min/max
- Set black and white points for the blue channel to the blue data min/max
- Apply a tone curve, control points=0,255,255,0
The first three steps align the channels to remove the orange cast, the fourth step inverts the negative. What’s left is what the film emulsion layers recorded, which obviously need white balancing.
What I’m trying to point out is that the saturated green is what the film recorded.