>>3112965A lens can only focus absolute to 1 plane.
Film has 3 separate layers (planes)
1 red, 1 green, and 1 blue
The lens focuses on the middle layer, so that layer is sharper.
On Kodak film, that layer was red. So Kodak film shot better skin tones
On Fuji film, that layer was green. So Fuji shot better landscapes
On Agfa film, that layer was Blue. So Agfa film shot better water and sky.
That is why their packaging was the color it was
