What stage of life did the green room represent

Green represents the growth of youth

Explanation:

According to the book, it is evident that green represents the change, hope, fertility, and general growth. When heaven and earth are brought together, a mystic color is formed which is green which brings the emotions of warmth to the planet.

Prospero decorates each room using diverse colors. Each room had a specific representation. However, he was stroke dead by fire at night, and he revealed himself to be gone. This was to show that even him did not escape the red death.