The uniforms contrast. On top of that, Cambridge is fairly sure Tom Paris hasn't served on a Galaxy-class starship. Perhaps he's utterly wrong about that, but...

He steps up and pokes Tom hard in the shoulder. Definitely real, as far as real can be trusted; he then gives a little tug on Tom's collar to show his rank insignia. Lieutenant.

"Oh, it's Lieutenant Paris," he says. "Well, then."