System Settings/Application Style

    From KDE UserBase Wiki

    Widget Style

    Widgets are the interface elements such as buttons, scroll bars, tabs and so on. Here you can choose and configure the widget style used for all KDE applications. You can also fine tune widget behaviour.

    Windows Decorations

    This module allows you to select a style for the buttons and borders around windows.

    GNOME Application Style (GTK)

    Configure the look of the GTK application