I made it so that you can receive Fonts/background colors/font colors if the message style was updated for it (not all styles can use it so I couldn't make it just work for all of them). I also did some patches relating to the overall background images recently, but that's a for something different ...
Not in the current Adium, but it is planned. Should I be excited for it to come in the near future? Also, I'm curious as to how it would be implemented. Would it be undefined things are filled in with custom colors, or would there be a keyword we would use in the CSS? Near future could be six days ...