SUMMARY

Dolphins folders view pannel color remains white under gnome if you've changed qt theming to adwaita dark.  


STEPS TO REPRODUCE
1.  Install dolphin, gnome-shell, qt5ct and gnome extra themes. 
2. Choose adwaita-dark via qt5ct.
3. Launch dolphin.

OBSERVED RESULT

Folders view pannel remains white despite the folders text being light.

EXPECTED RESULT

Dark grey background similar to the native app Nautilus. 

SOFTWARE/OS VERSIONS
Operating System: Arch Linux
Gnome:41.2
KDE Plasma Version: 5.23.4
KDE Frameworks Version: 5.89.0
Qt Version: 5.15.2
Kernel Version: 5.15.7-arch1-1 (64-bit)
Graphics Platform: X11
Processors: 8 × Intel® Core™ i7-10510U CPU @ 1.80GHz
Memory: 15.4 GiB of RAM
Graphics Processor: Mesa Intel® UHD Graphics


ADDITIONAL INFORMATION


See this answer:https://unix.stackexchange.com/a/683366/507025

Dolphin is better then Nautilus and many possible Gnome users which could become Dolphin users might be put off by not being able to figure out how to make Dolphin follow Gnome's dark theme. Dolphin apparently expects to find the color of the background in the file `~/.config/kdeglobals`. One way around this if you are simply using Gnome is to go and set the variable there. However, if in the same machine you have both Plasma and Gnome sessions, altering this file will mess with plasma theming.