In Color, photos taken through the app are shared through proximity, something which amasses a list of your contacts through machine learning; in effect, you'll be able to see all photos around you that were taken with Color. You'll be able to see the Color photos of the guy sitting two tables away from you at Starbucks, but when he finishes his caramel macchiato and leaves the coffee shop, you can't see them anymore. But if you spend a lot of time in proximity to someone--an office-mate, for example--that person's photos will gradually begin to stay in your contacts list for longer. It's an "elastic network," Nguyen calls it. "The whole goal is to say hello."