At a Fleet Overview page, there is a combobox with all your fleets
When you click it, it will open the list with the following colors:
fleet on route
#dd1111">moved under 10 minutes ago
#dd5500">moved under 1 hour ago
#eedd33">moved under 1 day ago
#00cc33">moved under 1 week ago
the list is ordered by on route, user order, fleet name