A theme is a group of coordinated settings that specifies how a desktop component or a group of desktop components appears. You can use themes to modify and control the appearance of the desktop in a consistent manner. When you apply a theme, the system modifies many desktop components simultaneously to achieve the desired effect. For example, if you apply a theme that increases the font size across the desktop, the theme also modifies the size of panels and icons on the desktop for optimum compatibility with the font size. Some themes have suggested font settings that may optionally be auto-set; in addition, most colors within a theme can be customized.
A theme contains settings that affect different parts of the desktop:
The controls setting for a theme determines the visual appearance of all windows, applications, panels, and panel applications. The controls setting also determines the visual appearance of the GNOME-compliant interface items that appear on windows, applications, panels, and panel applications such as menus, icons, and buttons. Some of the control options that are available in the desktop are designed for special accessibility needs.
The window frame setting determines the appearance of the border around windows only.
The icon setting determines the appearance of icons on panels and on the desktop background.