As I prepared to post to the 'List of all Suggestion', I could not find this one. I thought I made this suggestion before. But as the original seems lost, I felt it worthwhile to mention again.
Ideally, options would include the following:
*Size, position, and font used
*Colors used for different types of messages
*Number of tabs displayed
*What message type goes into each tab
*Where messages are sent when entered into a particular tab
Messages can be received from world, realm, local, system, party, guild (when implemented), whisper, and custom chat (I think that is all). They can be sent to any of the same list except system. There may be additional limited channels for HCS staff and moderators (if implemented).