What is the significance of the green light to Gatsby, Daisy, Nick, or the other characters in The Great Gatsby?
The green light at the end of Daisy's pier, a light to which Gatsby reaches out one dark night under Nick's observance, is symbolic of the hope that Gatsby holds to recapture the past with Daisy. It is his "go ahead" light that is attached to the color of money, which Gatsby knows impresses Daisy.
After he has amassed a fortune and has had a pretentious mansion constructed across the bay from the Buchanans, Gatsby is ready to recapture the past. He initiates magnificent parties, transporting famous guests to be fed by a corps of caterers. There is an orchestra that entertains the guests. Even a real bar with a brass rail is set up, and
...stocked with cordials so long forgotten that most of the female guests were too young to know one from the other.
After Nick arranges a meeting of Jay Gatsby and Daisy Buchanan at his cottage, Gatsby has a "greenhouse" of flowers sent to the cottage. With this color of renewal surrounding Daisy, Gatsby hopes to renew their old relationship. Later, Jay invites Daisy to his home in order to impress her as he displays his wealth by showing her his dresser that is "garnished with a toilette set of pure dull gold," a set that Daisy picks up with delight. When he shows her his custom-made shirts, she buries her head in them and "cried stormily," saying that the shirts are so beautiful. Interestingly, Fitzgerald mentions an "apple-green" shirt, that, perhaps, suggests Daisy's connection to Gatsby's obsession with wealth since his desire for her has tempted him into his lucrative, but criminal activities.
Then, after showing Daisy and Nick around the grounds and the swimming pool, Gatsby observes,
"If it weren't for the mist we could see your home across the bay....You always have a green light that burns all night at the end of your dock."
Nick notices that Daisy says nothing, but simply puts her arm through his while Gatsby, instead, appears to be absorbed in what he has just said. Nick concludes,
Possibly it had occurred to him that the colossal significance of that light had now vanished forever....Now it was again a green light on a dock. His count of enchanted objects had diminished by one.
Clearly, Daisy has not fulfilled Gatsby's dreams of what she has been to him. Instead, she has "tumbled short of his dreams." Although he is later lured again by her voice, Gatsby's confusion of economic value with moral and emotional values collides in his relationship with Daisy. For, she is not the magical creature he has imagined her to be, and he is unable to recapture the ethereal emotion of the past. Nevertheless, he continues to strive toward his dream of recapturing the romanticism and idealism of his youthful dream, the green light.
This element of optimism in Jay Gatsby's personality is something to be admired, Nick notes at the novel's end. Gravely disappointed in the East and the materialistic people who populate it, Nick Carraway returns to the West as the "green breast of a new world" [Enotes] with dreams of the future "green light" to be attained.
Gatsby believed in the green light, the orgastic [sic] future that year by year recedes before us. It eluded us then, but that's no matter--tomorrow we will run faster, stretch out our arms farther...
The green light, then, becomes the hope and dream for the future, the freshness and renewal that comes in nature and life. This light has been these things for Jay Gatsby, but just as he once stretched his empty arms toward the pier's end, the dream has been impossible for him to to grab.