If you want to create a customized theme for Lotus Quickr (Services for Domino) you normally start with one of the default themes. I wanted to use the default theme "Quickr (with classic navigation)" and so I activated this theme and afterwards clicked on "Custom Themes" -> "Create Custom Theme". What I now expected was that if I activate the "Generate" option for all HTML/CSS files I will get the original version of the theme I had activated before ("Quickr (with classic navigation)").
Unfortunately this seems not to be the case. What I did get was the CSS file of the old Quickplace theme ("Quickplace Classic") and some HTML files which do not match with any of the standard themes.
So if you want to use a standard theme as starting point for a new theme you should copy the 6 files (StyleSheet.css, Page.htm, Edit.htm, Headlines.htm, ListFolder.htm and SlideShow.htm) from the directory on the server (look here which theme corresponds to which directory). Then you should drag & drop all of the six files to your newly created theme. Then you can start to modify the files as you want.