Desaturate a hue when there is too much of it

FUEL has a day-night cycle where night is heavily blue tinted.

I'm looking for a shader that can desaturate a specific range of hues based on the amount of it on screen with an adjustable curve.
A combination of prod80's Color Gradients and Color Isolation would do. (apply color gradients to an isolated color only)
It needs to work on reshade 4.5.1