when you go on the princess app to fill out your paperwork it tells you your are in the blue lane.
this is just the status of your process of filling out your paperwork.
I found I filled everything out but was still in the blue lane, you have to do all the medallions to get into the green lane.
I heard there are lines once you get to the port to get you medallions that you need before you go through security. I paid $10 to have them sent to me, when I was talking to princess she did ask me if we had got the beverage package (which we had not) it would be free to ship. hope this clears up some
of the questions about the blue and green lanes.