“ Default is to collapse the material. Any value will have this effect (i.e. |expand=Template:!mxt and |collapse=Template:!mxt will not work as expected) . |bg=Sets the background color of the collapsed material. Defaults to #CCFFCC, a green hue. Named colors are listed at List of colors. For example, {{collapse top|This is the title text|bg=#F0F2F5}} or {{collapse top|This is the title text|bg=LightGrey}} (HTML color codes require the leading #) . ”