A short while ago, I wrote up and quick tutorial to create a new look and feel to your CDF pages.
http://wiki.pentaho.com/display/COM/Creating a new dashboard look and feel
In there, I wrote:
In order to replace the CE demo look and feel with my own, I needed to make changes to the template-dashboard.html file.
You can then proceed to create the template as indicated in the linked page above. To
To call up the dashboard page with the new template, add
the template parameter to the URL http://localhost:8080/pentaho/content/pentaho-cdf/RenderXCDF?solution=bi-developers&path=/dashboard-custom&action=custom.xcdf&template=templatename