The characters of Jack and Diane were originally supposed to be assassins. Although this point was eliminated from the final draft of the script, some of the dialogue still alludes to this, especially when they discuss the legitimacy of what they do and what they represent.
Jack and Diane wear the colors of red and blue, respectively. This was meant to signify their differing philosophical ideals, as compared to the colors of the two major political parties of the United States. Thus Jack's red aligns him with the Republicans and Diane's blue aligns her with the Democrats. The Gentleman's green colored shirt was meant to signify a third way (or approach) to life.
All the dialogue had to be re-dubbed after the microphone that was used on the set failed to pick up any of the actor's voices.