If you switch to a dark or other colored theme the UI just changes partly. Maybe its an issue with ultra wide screens (my resolution is 3440x1440).
Same behavior is in the 18.104.22.168 release.
Steps to Reproduce:
changing the theme color, UI color changes just partly
full colored UI
User Profile Reset: No
[Information automatically included from LibreOffice]
[Information guessed from browser]
OS: Windows (All)
OS is 64bit: yes
Created attachment 183861 [details]
screenshot of ultrawide screen - theme bug
*** This bug has been marked as a duplicate of bug 131023 ***