Final answer:
In Sartre's modern version, Orestes possesses a 'clean conscience' after his actions, indicating an individual moral autonomy that contrasts with the fear and fate-driven ethos of characters in traditional Greek tragedies by Aeschylus, Sophocles, and Euripides.
Step-by-step explanation:
In the modern version of the play by Sartre, the phrase 'though he has "red hands," he will have a "clean conscience"' implies that Orestes will not be troubled by his actions from an ethical or moral standpoint, unlike how characters in Aeschylus' version might have feared the consequences of their deeds. In Greek tragedy, particularly in the works of Sophocles and Euripides, the tension between human action, divine will, and personal responsibility is often explored.
While characters like Oedipus in Sophocles' plays are depicted as tragic heroes who accept responsibility for their actions despite the influence of fate, Sartre's interpretation appears to focus on an existential view where Orestes transcends prescribed moral imperatives imposed by the gods or society, thereby aligning his actions with a philosophical concept of a 'clean conscience'. This distinction illustrates the evolution of tragic characters from being subject to fate and divine retribution to asserting individual moral autonomy in modern interpretations.