On Saturday 21 April 2012 13:47:57 Martin Gr��lin wrote:

> > > systemsettings -> Application Appearance -> Style -> Widget style:
> > > Plastique
> > 
> > I have set plastik in kcontrol-appearnce-style, which is obviously ignored
> > by kwin.
> that's why I wrote "systemsettings". Obviously KWin is a Qt 4 application and 
> needs to have a configured Qt4 style and not a Qt3 style.

qtconfig also does not affect Kwin4. To change its settings one have to install
KDE4 desktop.