Version: (using KDE 4.3.0) OS: Linux Installed from: Gentoo Packages There seems to be no way in KDE 4.3 to configure the plasma-theme and background-image etc via system-settings, e.g. where all other desktop-appearance settings are. The only way to do this is by right-clicking the desktop and choosing "Settings". I think this is bad because if you want to configure your KDE desktop appearance you cannot do this from a central starting point but instead need to know that you have to look at two totally different places to access all available desktop-settings. I would consider this a usability bug.
This is especially important because plasma is not only used on the desktop, but also in applications (Amarok, ...). People who use a different desktop but run KDE4 applications need a way to change the theme. As for changing the background, that is bug 155056.
This is exactly bug #155056 :-) *** This bug has been marked as a duplicate of bug 155056 ***