So, I'm visiting this board for the first time from a computer here at COD, and the first 5 links are purple (clicked on) insted of blue.

Odd. I wonder if someone else here visits 4-ch.

Actually, it might have to do with the fact that the first five links just go to the main page, since those threads are already on the main page. I don't know how most browsers handle that...

First five links in the sidebar or the bunch of thread links on the top? First few thread links point to the same page and some browsers make them purple because you are already on the page, or maybe you already scrolled to the point where the links point to.