How can I make new/recently replied-to threads have text appear as a different color?

[MrSquid]

Do any of you know where I'd go to make new threads (or threads with new replies) show up not only as bold, but also as a specified color? It looks to me like it might have something to do with the go-to-first-unread class, but I'm not 100% sure, nor do I know where to try inserting color tags to make it happen.

Thanks!