Despite the fact that they carry no luggage, at the beginning and end of the movie Irene is wearing a light blue jacket that matches her pants. In the middle of the movie she wears a dark blue sweater that matches her shirt.
Sorry...not a slipup. The blue sweater that she is wearing in the middle of the film, she is wearing it the whole movie. The sweater is very small, and the sleeves are very short. When she is wearing her tan jacket it covers the sweater completely. Try paying a little more attention next time.