Automatically Changing Message Colors/Fonts in Outlook
Conditional formatting is a way to make messages that meet defined conditions stand out in the message list by using color, fonts, and styles. You specify conditions that an incoming message should meet, such as a sender’s name or email address, and then conditional formatting is applied only to those messages. You may have set up categories to organize your emails; you can also use conditional formatting to change the font color of the entire message to match any given category.
This feature is not currently available for Mac.