content: use AppleScript version "2.4" -- Yosemite (10.10) or later
  use scripting additions
  use O : script "omnifocus"
  use OmniFocus : application "OmniFocus"
  
  on run
  	tell O to toggleColon(selectedItems())
  end run
  
  on handle_string(argv)
  	if argv is "set" then
  		O's setColon(selectedItems() of O)
  	else if argv is "clear" then
  		O's clearColon(selectedItems() of O)
  	end if
  end handle_string