SUMMARY Confusion can arise from there being no good visual confirmation of the folder that is to be targeted for a drop. Dolphin will benefit from a visual hint that is _properly_ visible. STEPS TO REPRODUCE 1. Breeze Light colours (the default) 2. details view mode 3. open a tab to a directory with some files and a tree of subdirectories 4. disclose (expand) the tree 5. split view 6. in the left pane, select files 7. drag 8. in the right pane, without dropping, hover over one subdirectory, then another OBSERVED RESULT 9. the targeted directory becomes _less_ visible * marginally decreased contrast * the dark outline of the folder icon becomes marginally less dark EXPECTED RESULT 9. the targeted directory should become _more_ visible, should be _distinguished_ * the one folder icon should be significantly, unmistakably different from other folder icons * consider a change of colour from light to dark for the fill within the outline of the folder icon. SOFTWARE/OS VERSIONS Operating System: FreeBSD 14.0 KDE Plasma Version: 5.24.2 KDE Frameworks Version: 5.91.0 Qt Version: 5.15.2 Kernel Version: 14.0-CURRENT (64-bit) Graphics Platform: X11 Memory: 15.9 GiB of RAM Graphics Processor: AMD TURKS ADDITIONAL INFORMATION The (looping animated GIF) screen recording at <https://forums.freebsd.org/posts/559421> demonstrates this bug. Identification of the bug followed a period of disorientation, during which the change in appearance of targeted folder icons was – effectively – entirely invisible to the end user (the topic began at <https://forums.freebsd.org/threads/84361/>).
This is an issue with the application style you're using, which is not Breeze. You're using the Breeze Light *color scheme*, but the style decides which colors to use where and how to represent hovered items. You should report it to whoever makes that theme. Looks like Fusion? In that case it would be the Qt people.
(In reply to Nate Graham from comment #1) True! Thank you, apologies for the noise. The application style was 'cleanlooks', I can't recall where I found it.