That's a stretch. To begin with, you can't even see the blue/green difference until you actually send a message to someone. All received messages are gray. A

That's a stretch. To begin with, you can't even see the blue/green difference until you actually send a message to someone. All received messages are gray. And even without the color, you instantly know the difference between the two -- one tells you it was delivered, the other one is a shot into the void.