You can change the appearance of window borders, titlebars and buttons in KDE using window decorations. Some window decorations even have the capability to apply effects such as translucency. Window decorations must be able to do all these without sacrificing speed and performance. This is the reason why window decorations come in source code that must be compiled, or as binary packages that must be installed. Basically, Window decorations are plugins or small programs that instruct KWin, KDE's Window Manager, how to display window frames.

In order to add a new window decoration, you need to compile it from source code. If a binary package for your distribution or system is provided, you simply need to install it using your distribution's package manager. Please refer to your distribution's manual for instructions on how to do this. Once the window decoration has been installed, it can be accessed in the Window Decorations settings in the KDE Control Center. In the Window Decoration tab, a list of installed window decorations can be seen in the drop down box. Simply select the decoration you want to use and click on Apply. Different window decorations have different capabilities and settings. Play around with the different options available. The Buttons tab allows you to control the buttons on the window titlebar. Enable the Use custom titlebar button positions check box in order to rearrange, remove, or add buttons. To add buttons to the titlebar, drag an item from the list to the titlebar preview above it. To remove a button, drag the button from the titlebar preview to the item list. Simply drag buttons in the titlebar preview to rearrange them.

While all window decorations need to be compiled from source code, some window decorations can load pixmap-based theme files that do not need to be compiled. KDE ships with a pixmap-based window decoration called the IceWM window decoration. Another pixmap-based window decoration is deKorator, which can be found on kde-look.org. Please refer to your distribution's documentation on how to install these. The advantage of using pixmap-based window decorations is it is relatively easy to make themes for them, by using images and editing a configuration file. The tradeoff is a slight loss of performance, while this may be unnoticeable on very fast systems.

To add an IceWM theme, select IceWM as the window decoration and click on the Open KDE's IceWM theme folder link in the window decoration description area. This will open a Konqueror window to $KDEHOME/share/apps/kwin/icewm-themes. Extract your IceWM theme to this folder. The theme will then be added to the list of IceWM themes. Select the theme you want to use and click on Apply.

To add a deKorator theme after you've installed deKorator, select deKorator from the window decorations list and go to the Themes tab. Click on Install New Theme and locate your deKorator theme archive. Make sure that the version of the deKorator theme matches the deKorator version installed on your system. Once the theme has been added, select the theme you want to use and click on Set Theme Paths. Click on Apply for the changes to take effect.

Some more window decorations are available at kde-look.org under the Native KDE 3.x and the Native KDE 3.2+ subsections. Themes for the IceWM and deKorator window decorations have their own subsections under the Window Decorations category.