I changed some javascript, but there is still an error when choosing a color in ie (move mouse to the bottom of the colorpicker) - maybe you can check if this occurs also on another installation than my demo site.
Instructions:
-install cb_customizetab.zip as CB plugin
-configure default template for the plugin in the backend
-install cb_template_switcher.zip as template and assign it to CB or set as default
Now users can choose their base template and customize it.