CVar colorChatNamesByClass

This CVar changes how the chat log is displayed. Instead of the names of people speaking being the same color as their text, their name will change to a color to match their class.

• 0

• 0 :Name of person and chat text all 1 color
• 1 :Name of person is a different color based on their class

If this setting is on, the following happens

• Death Knight's Name : Text
• Druid's Name : Text
• Hunter's Name : Text
• Mage's Name : Text
• Paladin's Name : Text
• Priest's Name : Text
• Rogue's Name : Text
• Shaman's Name : Text
• Warlock's Name : Text
• Warrior's Name : Text

You can change this setting via the Interface settings.

or

In-game, type the following /console colorChatNamesByClass setting

or

You can exit wow, open the Config-cache.wtf file, and add the following line: SET colorChatNamesByClass setting