Paul Ford wrote a great post about the significance of the blue/green bubbles in the Messages app on iOS. From It’s Kind of Cheesy Being Green:

This spontaneous anti-green-bubble brigade is an interesting example of how sometimes very subtle product decisions in technology influence the way culture works. Apple uses a soothing, on-brand blue for messages in its own texting platform, and a green akin to that of the Android robot logo for people texting from outside its ecosystem. […]

There are all sorts of reasons for them to use different colors. (iMessage texts are seen as data, not charged on a per-text basis, and so the different colors allow people to register how much a given conversation will cost—useful!) However, one result of that decision is that a goofy class war is playing out over digital bubble colors. Their decision has observable social consequences.

This then turns into a post about product management, in a way that only Ford can do. Great stuff.