Do you mean search results? Which version of LW do you have? I remember (unless my memory tricks me) the earlier versions of LW listed those people who were not properly configured & had firewall issues were listed as red.
If you've been using the Spam filter in the late 4.9 series of LW, then it would list those results that fitted a spam criteria in red that you'd already set. So the red would represent a filtered result or those that represented a filtering sequence you'd previously used.
Sponsored links. Yes you're better off leaving those alone. I've never seen them but, here's what a simple search using the term SPONSOR* found: 1.
http://www.gnutellaforums.com/showth...ght=sponsor%2A
2.
http://www.gnutellaforums.com/showth...ght=sponsor%2A