[BirdOPrey5]

This is all controlled by the HTML Markup box in the Usergroup Manager when you edit a specific usergroup.

There are 2 boxes where you put in the opening and closing HTML tags or "markup."

For example to make the names bold you'd enter:

<strong>
into the first box

and

</strong>
into the second box.

This will also affect the username in the psotbit as well. There's no built in way to only change the username in whosonline/visited.