Originally Posted by Dakota rube
Fitzgerald was a pretty gifted symbolist. Remember Jay Gatsby staring off into the distance at the green light situated on the end of Daisy's dock in East Egg? In this case, I think Fitz used green to describe the American Dream of wealth and prestige, embodied in Daisy. The Valley of Ashes? Dr. Eckleburg's eyes?
Yes, like that. I had thought perhaps the red, blue, and green might refer to a red light district. And that might foreshadow the mentioning of incest in the plot.