I'm talking about the panel launcher icons (as per my original post) that most users assign to their panel by clicking a menu item and then 'add to panel'. The resulting launcher arrives on the panel in the theme already chosen such as 'Breeze', 'Oxygen' etc. Not everyone wants this. They might be happy with the default folder and system icons but prefer to assign a different icon to one, some or all of their panel launchers. This is no longer possible as of the last KDE framework update.