What's with the icons here?

[steyr_m]

Sometimes they're grey, sometimes blue, sometimes red.

Sometimes the envelope is open, sometimes closed.

I can't seem to see a definite pattern here.

[Dogman]

Icon Legend

http://gold-silver.us/forum/images/statusicon/thread_new-16.pngContains unread postshttp://gold-silver.us/forum/images/statusicon/thread-16-right.pngContains no unread postshttp://gold-silver.us/forum/images/statusicon/thread_hot_new-16.pngHot thread with unread postshttp://gold-silver.us/forum/images/statusicon/thread_hot-16.pngHot thread with no unread postshttp://gold-silver.us/forum/images/statusicon/thread_lock-16.pngThread is closedhttp://gold-silver.us/forum/images/statusicon/thread_dot-16-right.pngYou have posted in this thread

Bottom left of the sub forum