Some preliminary workarounds/explanations here:
Appearance of Nautilus and other apps: The GNOME project keeps moving more and more apps to libadwaita
theming, the latest being, among others, the file manager Nautilus. This means that it no longer respects the system GTK widget theme (as set in e.g. Budgie Desktop Settings), and also might not adjust to dark themes correctly.
For the second problem (not adjusting to dark system themes) there are two possible solutions. One is to open gnome-control-center
(from a terminal in Budgie as it's not shown in the menu anymore), navigate to the "Appearance" section and switch between "Default" and "Dark" there. Note that libadwaita
has some integrated dark theme detection, which will automatically switch to dark mode, if your widget theme ends in "-Dark
". I'd have to research how to override that if that's not what you want.

The other possible solution using dconf-editor
is described here: https://discuss.getsol.us/d/8463-fix-for-dark-themes-with-blaring-white-applications
For the first problem (not respecting system theme) one solution/workaround is to patch the libadwaita theme to match your system widget theme colour. An easy way to do this is by using the Gradience app. Currently available as a flatpak here but we'll probably see about integrating it into the Solus repository soon. With this app you can either manually adjust the theme colours (if you have the time and inclination to do that) or, as I did, explore pre-configured presets. Personally I use our ant-dracula-gtk-theme
, so I searched for the Dracula preset and applied it. This will adjust the libadwaita
theme colours to match the widget theme. Not perfect, but much more agreeable to the eyes.

So much for the previously known issues. Some of the stuff mentioned in this thread was new to me. I'll have to do some research on those issues.
Sorry for any possible errors in this post. Written in somewhat of a rush before I have to leave my apartment.