there was a dark colour sheme so i applyed this. thx
But in general this hole theme-setting stuff is annoying. In my opionion it is too complicated.
If i want a dark theme i want too choose it just once and all the stuff wich is related to this theme should be apllied automatically. Otherwise you have too click trhough at least 3 options in system-settings.
Beside that there should be a option for the taskbar to choose the icon size. Right now the only way to do this is to resize the panel.