Sets various appearance parameters for this outline item.
Param is a PdfParam object or parameter string
specifying the following parameters:
- Bold (optional) - if set to True, the item's text appears in bold. False by default.
- Italic (optional) - if set to True, the item's text appears in italic. False by default.
- Expanded (optional) - if set to False, the item will initially appear collapsed (closed). True by default.
- Color (optional) - specifies the item's color by name or hex number. Black by default.
- R, G, B (optional): an alternative way to specify the item's color