What to wear to a Grad party?

I am attending my boyfriend's graduation party, and even though I know he thinks I look good in whatever I wear, I want to look very nice since it is his graduation party. I want something that is flattering but not clingy or provocative. I love Zooey Deschanel's style. I was thinking something like this:

http://store.delias.com/item.do?itemID=56525&categ...

But, I don't like pink to an extreme, and there is not a Delia*s in my area. Any suggestions would be greatly appreciated, Thanks!