[FFmpeg-user] red-shift and blue-shift

[Paul B Mahol]

On 3/4/20, Michael Koch <astroelectronic at t-online.de> wrote:
> Hi,
>
> is there any known workaround for making a red-shift or a blue-shift? I
> mean shifting the visible spectrum towards red or blue. In the middle of
> the spectrum this can be realized by the "hue" filter, but at the end of
> the spectrum I want a different behaviour. I want a shift instead of a
> rotation. Colors at the end of the visible spectrum must be shifted to
> (or from) black.

Can't this be done with lut filters?

Can you describe math behind this shifting more precisely?
If possible in RGB.