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.
While this is certainly possible, another approach is to leave the current dashboard templates alone and create a new set of dashboard templates. In this way, it may even be possible to use different templates withing the same solution.
All dashboard template reside in this directory:
In order to create a new template, simply insert a new file in this directory, and name it as follows:
Note: In the file name above, only the "templatename" portion may be changed. everything else must remain as indicated.
You can then proceed to create the template as indicated in the linked page above.
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