You should enumerate those “other online suggestions”, so we are not redundant with recommendations. You also did not mention if it is the Air screen, or an external monitor.
In System Preferences : Displays, there are three areas that you can manipulate to alter screen color and/or brightness:
- Display tab
- Are you using Automatically adjust brightness?
- Are you in a bright, or dimly lit room?
- What happens when you switch auto brightness off, and use the slider adjustment?
- Color tab
- Experiment with the available color profiles. Display P3 will brighten things up.
- Create a custom color profile tailored to your preference.
- Night Shift tab
Disable Nightshift, and gauge this result. I would not recommend altering the Color Temperature slider.