For "Seasonal", I decided to try a bit of ASP generated CSS. I created a script that, when fed a specially designed CSS file, spits out that same file modified with "seasonal" colors. Depending on the month, it generates certain color sets. I tried using PSP's colors, but my wife said January shouldn't be orange, so between her and I we created this:
Now the Image Game, sociate.us, and this blog all use the new seasonal color set.