Similar to "levels adjustment" brightness improvement with ffmpeg
You could possibly use the curves filter. It has a lighter preset:

ffmpeg -i input -vf curves=preset=lighter -c:a copy output


The red, green, and blue components can be adjusted separately. The following is the same as what the lighter preset uses:

curves=r='0.4/0.5':g='0.4/0.5':b='0.4/0.5'


Additionally you can make your own curves preset in Photoshop, export it as an .acv file, and then the curves filter can utilize it:

curves=psfile=/path/to/ps_curves_file.acv