You can create style swatches — with CSS, SCSS and Compass, or Stylus and nib — over at http://sw4tch.com. Then you can add the swatches to a new swatchbook that you can use as a canonical reference for all project styles.
You can fork each others swatches to suggest changes or publish github gists to share code.
I've been using this on a project for the last 3 weeks and it's helped greatly with communication between the development and design teams.
OK, this is self-serving... I built sw4tch but I'm really proud of it and I've been getting great value from it so far.
Thanks for reading,