Only an Administrator user can select the Share theme.
  Any change to the theme will affect all users of the SkyVault
  instance from the next time that they log in or from a browser
  refresh.
    The installation wizards install the default theme and the sample alternative themes.
      The available themes are installed in the
        <configRootShare>/classes/alfresco/site-data/themes
      directory.
    - 
        On the toolbar, expand the More menu and click
            Application in the Tools list.
        
The Options page appears.
 - 
        Select the required theme from the menu:
        
- Green Theme
 - Yellow Theme
 - High Contrast Theme
 - Default Theme
 - Google Docs Theme
 
 - Click Apply.
 
The new theme displays in Share. The new theme persists across sessions.