Themes are used to configure the way how the window manager looks. Things like fonts, colors, border sizes, button pixmaps can be configured. Together these things form a theme.
Theme files are searched in the following search path:
$HOME/.icewm/themes/
/etc/X11/icewm/themes/
/usr/X11R6/lib/X11/icewm/themes/
or /usr/local/lib/X11/icewm/themes/
(compilation dependant)The theme to use is specified using Theme
configuration option or
-t
command line options in the preferences file.
These directories usually contain other directories that contain related theme files and their .xpm files. Each theme file specifies fonts, colors, border sizes, ...