<font color=#be6400>...</font>.
Screenshot (see PStamatiou): http://img705.imageshack.us/img705/2719/hnscreenshot.pngI've never seen this before. It does seem that the users with orange names may be connected with YC companies, though it seems somewhat random even then. Is this a new feature, or related to [1] which seemed to later be killed in [2]?
EDIT: The username is no longer highlighted in the article comment I pointed out above, so this may somehow be time dependent.
[1] http://ycombinator.com/newsnews.html#4feb09
[2] http://www.paulgraham.com/hackernews.html