I can definitely change it if people want! Not difficult at all. I chose blue because it's my favorite color, but no reason we can't return to the green or purple. Though I'm afraid I don't remember the purple boards, either because I wasn't around at that point or because my memory's gone bad (either is likely, lol)
The purple forums were '06 and before. I think '05 was the first Janno, but I didn't show up til '06, so I'm not entirely sure. The green forums came in December '06 for Janno '07.
A lot of people complained about the purple forums, but they grew on you. We had a pretty good group in '06, stayed pretty active all thru that summer. Sadly, with very few exceptions, they're all long inactive.