In QGIS it's easy to change background color of the map canvas, but is there a way to do the same for the Layers Panel ? In cases of very light colored styles these appear not so clear (if at all) on a white background. I know that in QGIS 3 there is an option to toggle GUI theme from default to Night Mapping, wich turns anything into darkness, but is there a way to set Layers Panel background to e.g. black independantly from the GUI theme? Python perhaps?
there's a plugin called Load QSS - UI Themes that's available in QGIS 2 and 3. This comes with about 10 or so themes you can use, beyond the standard light/dark themes.
You can come up with your own themes - QSS is very like CSS, but for Qt Widgets. If you write your own it's likely you'll be able to customise a specific widget like the Layers box.
It's been a few years since i tried QSS so i'm not sure whether you can style the layers dock specifically, but at the least, all docks could be styled to contrast with the canvas and toolbars.