The most obvious break from traditional film noir that Pulp Fiction makes is by being shot in color. The iconic image of this style of filmmaking is a perception arrived at through its very name. Film noir means dark film and one of its visual hallmarks is the symbolic use shadows and key lighting.
Pulp Fiction introduces a new genre and closes the gap between itself and traditional. A film noir without a femme fatale is hardly a film noir at all. Mia Wallace fulfills the role of femme fatale from the start by almost literally acting as a siren who calls forth Vincent Vega into her lair. The classic femme fatale is a dangerous temptress within whose trap a not-terribly-bright man falls and Mia is certainly seductive enough toward Vince to get him trapped almost to the point of devastation once they return back home. It is exactly at this point that the standard conventions of film noir begin to fall apart.
Film noir has a foundation of uncertainty and doubt that gives way to the darker impulses of the human mind. Upon returning back to Mia's house Vincent goes to the bathroom and engages in an interior debate over the intelligence of having sex with his boss' wife. In a standard film noir, any doubt naturally gives way to impulse rather than rationality. Vincent makes the decision to leave with a goodbye and it is only through the action of having doubts and that interior monologue that the subsequent events of the story take place and Mia goes into overdose. Film noir differs from conventional gangster, mobster, and detective movies through the introduction of shadows on the fringes of expected behavior; crooks can show goodness and law enforcement officers can become corrupt. The end is forecast equally well for both: destruction, probably in a violent way.
Vincent's decision to give up the satisfactions of giving into the attraction with Mia can be read as a foreshadowing of what eventually becomes the thematic power of the film. Pulp Fiction's narrative is a distinctly non-linear manner shot out of chronological order. Jules seems balanced to become an important character only to disappear entirely for an hour and then make reappearance in exactly the same scene with which he was introduced. That scene includes something rarely found in the dark world of film noir: a reference to the Holy Bible. Jules likes to quote from the Bible before he assassinates and there is in this custom a link back to the wrath of God against sinners. The absence of Jules from the middle section of the film is a necessity that accounts for the non-linear construction.
Vincent breaks with film noir tradition by rejecting the advances of a femme fatale, which is something that never happens in a classic noir film. Vincent's rejection is an indication of a more optimistic tone to be found in Pulp Fiction; a tone that contradicts the very root of film noir mechanics. Vincent's rejection of Mia is then compounded by the decision of Jules to reject his lifestyle. The middle part of the film of Pulp Fiction takes places after Jules has come to his decision to take his inexplicable escape from death in the opening of the film as a sign from God that it is time to walk away from his life as a hired assassin. If arranged chronologically the power of the scene in the diner would be taken away because it would become