Icon-only Task Manager: Highlighting open applications?

I have a number of icons on my Icon-only Task Manager for launchers that are shown when not running. (I am using KDE).

I don’t see a way to highlight when an application is running. (The only way to tell is to hover over it and see if there is a thumbnail of a running instance of that application).

I would like to be able to have the button highlighted in some way when the app is running. Is there such an option? Or can it be configured somehow? If not, can it be requested as a feature somewhere?

Thanks!

Looks messy, but the only way I’ve found is: Right Click on Taskbar | Icon-only Task Manager Settings | Appearance - Style - Use Indicators