Color of torrents

[Guest Kinson]

I've been a long time Bittorrent user. I've been wondering this from almost the start (since it has never affected anything_, but .. In the client, a torrent goes from having a blue arrow to a red arrow, and the bar that shows the % complete, also fills with red (upto the point where the torrent is at). It was blue, but I checked it recently and it is red (again, not the first time I've noticed this).

As I said, it has not affected the torrent, just wondering what the difference(s) is between the blue and red torrents.

Thanks in advance.

-- Kinson