SUMMARY
Set more contrast in the panel icons when the application is minimized.
You could also choose a different color, now it is almost invisible with both breeze and dark breeze.
This wasn't a problem with the old task manager, but with the new task manager (icons only) it is.

STEPS TO REPRODUCE
1. Open an application
2. minimize it
3. 
OBSERVED RESULT
you will notice that the contrast on the default themes is minimal, almost non-existent.


EXPECTED RESULT
the icon should show more prominently the application status.

SOFTWARE/OS VERSIONS
Windows: 
macOS: 
Linux/KDE Plasma: 
(available in About System)
KDE Plasma Version: 
KDE Frameworks Version: 
Qt Version: 

ADDITIONAL INFORMATION