We've been testing out different themes all day and for now, the default will have to be it. The multicolor one is interesting but I cannot set a default color and I HATE the default black one that comes up. Plus there seems to be a few technical issues with it. It would not text wrap when I was replying.
The swirly green one is not a go, I'm afraid. SMF 2.0 is so new that there aren't that many themes available that are compatible but I'll keep looking.