I just did the upgrade from 13.10 to 14.04 and the default KDE theme not looks like no theme at all:
I usually use KDE with Awesome WM as the window manager, but even without Awesome WM, this looks bad.
As far as I can tell, all oxygen packages that I could possibly need are installed:
i gtk2-engines-oxygen - Widget-Thema Oxygen für GTK+-Anwendungen
p gtk2-engines-oxygen:i386 - Widget-Thema Oxygen für GTK+-Anwendungen
i gtk3-engines-oxygen - Oxygen widget theme for GTK3-based applications
p gtk3-engines-oxygen:i386 - Oxygen widget theme for GTK3-based applications
i kde-style-oxygen - Oxygen widget style
p kde-style-oxygen:i386 - Oxygen widget style
i libreoffice-style-oxygen - office productivity suite -- Oxygen symbol style
i oxygen-cursor-theme - Oxygen mouse cursor theme
p oxygen-cursor-theme-extra - Oxygen mouse cursor theme - extra colors
i oxygen-icon-theme - Oxygen icon theme
p oxygen-icon-theme-complete - Oxygen icon theme - transitional package
p oxygen-molecule - GTK+ theme to match the Oxygen widget style
i ttf-oxygen-font-family - Oxygen font family
p ttf-oxygen-font-family:i386 - Oxygen font family
In the systemsettings, it does not show oxygen:
How can I get the Oxygen theme back?