I am posting the solution I found, I hope it might be useful for others.
I found a third party service - GrooveUI.com. They provide a UI for creating multiple themes for a website. The theme are enabled based on access URL.
This is close to what I was looking for.
Note: Links disabled by moderator edit.
I am developing a SaaS based web application. My requirement is that all my users can have custom look-n-feel of the application.
Are there some standard tools to implement this.
If this question has already been asked, please point me to it.