See
http://devtwo.com to see an example of what we currently use. We're looking to redesign our branding based on whatever new logo wins this competition.
Although we're partial to gray and blue, we ARE open to any color combination if you can make it work. The end goal here is something that represents top-notch design style and professionalism. We love building web applications and need a great design to match our passion.
Good luck to everyone.