Where is the filepath of the added theme?

Hi. firstly, pardon me for any bad english. i have a very simple question regarding jasperreport server. i logged in as jasperadmin and add a new theme and have modified it. now, i know you can download the theme from the interface but where can i find the exact directory for this saved theme. i looked at apache-tomcat/webapps/jasperserver/themes but my theme was not there? where does it store my custom theme? thanks

ADD: To make sure you guys understand what i really want, let me tell you my situation right now. i have updated from jasperserver 5 to 6. but my own custom theme is lost. luckily, i have made a backup of the webapps folder before upgrading. so i need to retrieve the custom theme from the backup folder so i could copy it to the upgraded one. so thats why i need to know where is the directory