The black icon indicates that at least one of the installed McAfee services (AntiVirus, Personal Firewall, SpamKiller, or Privacy Service) is not working (disabled, expired, or corrupt). Mouse-over the icon and it should tell you what service is disabled.
I'm assuming from your post that you have the full (paid/licensed) version of VirusScan and Personal Firewall. If so, you are still protected..just not from SPAM. Just uninstall the trial version of SpamKiller and the icon will turn red again, meaning everything's A-OK. If all three services were trial versions, then you are open for attack. In that case, get protection immediately. Free options include Zonelabs' ZoneAlarm Basic Firewall, as well as Avast Antivirus Home Edition. You can stick with these, or choose to buy the full version of McAfee, Norton, or another internet security suite.
Hope this helps,
I am currently using mcfee antivirus and firewall, i also went for the free trial of spam killer, now that my time is up a box appears everytime asking to subscribe and pay or just close. I always just close it but the my little icon turns from red to black. Anyone know whats going on? Is macfee still working properlly? Am i still safe?????