Themes are a way to gather together the properties that control the appearance of the editor.
The distribution comes with a themes directory which contains several themes. You can specify the theme to use by setting the theme property in your preferences file:
theme=AnokhaThe specified theme file is loaded as an additional preferences file after ~/.j/prefs is loaded.
You can use the themePath property to specify a list of directories that will be searched (in the specified order) for theme files when the full path of the theme file is not given. For example:
themePath=/home/peter:/home/peter/j/themes:/usr/local/share/j/themes