When using an icon theme different from the one in the plasma style, most icons in the system tray don't change, but every other icon in Plasma, including in the taskbar, launcher and on Plasmoids, does. The workaround would be to manually change icons in the Plasma theme but it is pretty cumbersome. I'm requesting in this report to make it so that the system tray can follow the icon theme specified by the user, even if it is changed.