Basically Color's built a way to be a vouyer into your friend's world. You request to "visit" a friend via the iPhone app, and if they hit accept, it sends you a direct video feed of what they're seeing right now (no audio). It also posts that feed onto Facebook so any of their friends can see the feed. It can last as short or as long as you'd like.
When I tried it out, I got to see people in Paris, Las Vegas and SF in the span of three minutes. It was a surreal experience.
There are more details in the article we wrote ( http://mashable.com/2011/09/22/color-for-facebook/ ), but the essential point is that you don't have to use it -- your FRIENDS ask you to use it, and thus you use it to appease your friends. It's very voyeuristic and that leads to a lot of interesting conversations.