Created attachment 152398 [details] local repro SUMMARY With the theme "Ark Dark" the Virtual desktops widget doe not show the icons of the applications that are currently opened. STEPS TO REPRODUCE 1. Have the virtual desktop widget visible in the taskbar 2. verify that the option to show icons is well enabled 3. change theme to Ark Dark : no icons 4. change theme to Ark Color: icons are well displayed SOFTWARE/OS VERSIONS Linux: 5.19.10-100.fc35.x86_64 KDE Plasma Version: 5.25.4
This means that the Arc Dark theme has an icon in it that overrides the icon of the app in question, and that icon is either broken or fails to respect the active color theme. You'll want to report this to the developers of the Ark Dark theme.