Well, the color of your website is going to vary on what your service is. For example, if you are a restaurant, you have to use the color red because the color red makes you feel hungrier (it's a study).
Since you said your site is an interactive social wiki, try using some light colors . I maybe wrong because the color of your site, as LastMitch has said before, will have to be played with. Unless you provide us a link to your site, we can pick colors for you (but you will have to play with them).
Here are some sites that can help you pick on color schemes:
http://www.colorcombos.com
http://inspiredm.com/colour-schemes/
http://designshack.net/articles/inspiration/25-awesome-tools-for-choosing-a-website-color-scheme/
http://vandelaydesign.com/blog/design/website-color-schemes/
http://tympanus.net/codrops/2011/12/08/25-examples-of-perfect-color-combinations-in-web-design/
http://www.onextrapixel.com/2010/11/25/what-does-your-websites-color-scheme-reveal-about-you/
http://www.colorcombos.com/2012-trends-in-website-colour-design-article.html
http://www.onextrapixel.com/2012/06/08/30-inspirational-examples-of-eye-catching-website-design/
http://speckyboy.com/2012/11/08/50-websites-with-fantastic-color-schemes/
It would be easier if we had the link to your site, but in the mean time, I google'd all this for you... if these don't help, use google!
BTW, sometimes having a black and white site can look extremely cool you know?
http://www.hongkiat.com/blog/showcase-of-beautiful-black-and-white-websites/
http://inspirationti.me/websites/grey/
Hope my post helped.