Speaking of defaults, NEVER SET DEFAULTS IN THE DATABASE. Not ever. The theme options you store in the DB should always, always, *always* be something the user has selected. If the user selects the default, then that’s fine to set in the DB. but you don’t set it in the DB just because it’s not set at all. get_theme_mod has a second option for the default value. So does get_option for that matter. Use this.
Otto Wood, WordPress Core Developer on Custom Admin Screens
Thanks, Otto, for clearing that up :)