Add the following lines so lighttpd reads a HEADER.txt file.
dir-listing.auto-layout = "disable"
dir-listing.show-header = "enable"
dir-listing.hide-header-file = "enable"
dir-listing.encode-header = "disable"
Then create a HEADER.txt file under /opt/piratebox/www/Shared/ and enter a style sheet.
<style type="text/css">
.body {}
/etc/init.d/piratebox stop
/etc/init.d/piratebox start
http://sylvain.naud.in/post/2013/06/16/Personnaliser-le-r%C3%A9pertoire-Lighttpd-de-votre-PirateBox#attachments [french]
http://forum.daviddarts.com/read.php?2,7469