I would like to make the dot (unread indicator) more substantial. I doesn't look to have any element designation that can be altered using CSS. The only thing I can find is in SP:
Title (Unread) (discussionListTitleUnread)
background: transparent url('@imagePath/xenforo/widgets/discussion-new.png') no-repeat right center;*/
So image replacement would be the only method, whether by direct replacement or calling up a new image path.