Color coding messages
Usually Outlook users are using folders to organize messages, but you can also use colors. For example, you might apply a special color to all messages from a particular person. You can then see at a glance which messages are from that person.
In previous versions of Microsoft Outlook, the Organize feature enabled you to create conditional text formatting rules for e-mail messages. In Microsoft Outlook 2010, conditional text formatting is now accessed in the Advanced View Settings dialog box.
For more details, see Conditional formatting.