Admincp----->usergroups----->usergroup manager------>choose usergroup to add mark up to....
4th box down (should be)------>Username HTML Markup
(Specify an opening and closing HTML tag with which to display the names of users in this group. This applies to names that appear on Logged-in Users, Who's Online, Users Browsing Forum, Users Browsing Thread, Posts, Member List etc.)
there are 2 boxes....in the left copy and paste this:
HTML Code:
<span style="color:red;"><b>
In the right box.....copy and paste this:
That will make the color red and the words bold, change as needed to suit your needs/wants
then in stall this:
https://vborg.vbsupport.ru/showthread.php?t=92149