I'm running openSUSE 42.1, Plasma version 5.5.5, Qt version 5.5.1.
Like the title says, the wrong icons are shown in the panel.

An image worth more than a thousand words...





This does not happen with dolphin or kate for example. And also I guess those monochrome icons were meant for the system tray only, or am I wrong?
Is there any way to fix this?