On my new Dell XPS 13 9370, it seems that the display backlight brightness is adjusted based on the brightness of whatever's on the screen.
For example, say I have Sublime Text open with a dark theme, and I click on the file menu. The menu dropdown has a light background, and this is enough to darken the entire screen. Moving the selection over to the "Selection" menu causes the screen to lighten back up again, because this menu is apparently small enough for it not to count.
You can see the effect here, as I switch between a larger and smaller menu:
I find this feature unpleasantly jarring as I navigate through menus and similar. Is it possible to turn it off?
In case it is relevant, my system specs are as follows:
- Dell XPS 13 (9370)
- Debian Linux (sid)
- Cinnamon DE