Window decorations
The appearance of window borders, titlebars and buttons.
You will need an engine and a theme.
KDE Style
The elements of a graphical user interface, such as buttons, scrollbars, tabs, and menus.
You will need an engine and a theme.
In this case - QtCurve,Emerald
The QtCurve is in the official Ubuntu repositories. The QtCurve engine can be installed with the package: qtcurve
Description: Unified window decoration for KDE and GTK+ (meta-package)
This package installs all packages related with QtCurve: *
kde-style-qtcurve * kwin-style-qtcurve * gtk2-engines-qtcurve *
qtcurve-i18n . QtCurve is a set of widget styles for KDE and GTK+.
It provides a consistent look between KDE and GTK+ applications,
which is easy on the eyes and visually pleasing. Homepage:
http://www.kde-look.org/content/show.php?content=40492
The Smaragd (Emerald for KDE): http://kde-look.org/content/show.php/?content=125162
Description: Smaragd is a window decoration engine for the KDE window
manager KWin. It allows you to use Emerald theme files (from
Compiz/Beryl) with KDE SC 4.
The Smaragd can be found from the PPA repositories: https://launchpad.net/ubuntu/+ppas?name_filter=smaragd
Download the deb and install it.
Ice cream Theme
Download - unpack the tar package.
Extract the Ice cream QtCurve.emerald to the $HOME/.emerald/theme.
KDE System Settings > Workspace Appearance > Window Decorations > Smaragd
KDE System Settings > Application Appearance > Style > Widget style: QtCurve -> Configure -> Import QtCurve Settings File
Open the archive and place its contents in '~/.themes'
'.themes' is located in your home folder. It's a hidden folder that you can make visible by pressing ctrl H.
If you don't have a '.themes' folder; create it.
With this method you are the only user that can use the theme. If you wish to install system-wide use the other answer.
Best Answer
Go to System settings -> Application appearance (or Workspace appearance).
In some items (Colors, Icons, etc) you have the option to:
In other items (Style):
There are other situations that involve compiling a theme, but that's a longer story.