Themes are often used to change the look and feel of a wide range of things at once, which makes them much less granular than allowing the user to set each option individually. For example, users might want the window-borders from a particular theme, but installing it would also alter the desktop background.
One method for dealing with this is to allow the user to select which parts of the theme they want to load; for example in Windows 98, users could load the background and screensaver from a theme, but leave the icons and sounds untouched.
Linux operating systems may support themes depending on their window managers and desktop environments. IceWM uses themes to customize its taskbar, window borders, and time format. WindowMaker can store colors for icons, menus, and window-borders in a theme, but this is independent of the wallpaper settings. GNOME and KDE use two independent sets of themes: one to alter the appearance of user interface elements (such as buttons, scroll bars or list elements), and another theme to customize the appearance of windows (such as, window borders and title bars).
Although Android does not support themes, the forked CyanogenMod and its successor LineageOS have native theme support. The CM theme engine is in turn used on many other forked Android ROMs, such as Paranoid Android.
Firefox and Google Chrome either support or supported a form of theme. Firefox (and its sibling Thunderbird) supports themes either through lightweight themes (formerly Personas) or complete themes. While lightweight themes are simply background images for toolbar Firefox toolbars, complete themes have more power to modify Firefox's appearance. Google Chrome version 3.0 or later allows themes to alter the appearance of the browser.Internet Explorer 5 and its immediate successor allowed the background picture of their toolbars to be customized.