SetBrightness for the whole game

Hi guys,
I would set the brightness for the whole game but I just find the Current scene option or a specific scene and when I change the scene the brightness back to previous value (100%).
How can I do it?

Many thanks.

Possible via the config.ini. see here.

Or via the setWindowBrightness() function.

Or via the openGL shader @ Lightness & Contrast. (shader toolkit script is required).

setWindowBrightness() is perfect.

Thanks.