First, from static green (that is, the green of various trees and landscapes) to dynamic green (wind and rain, sunshine are green);
Secondly, the types of green, from the description of colors appearing in various periods to black and surprising green, all describe the changes of green in spring.
Thirdly, from essential green to metaphorical green, he wrote that green in spring is the color and symbol of life.
On the one hand, the poet expressed his love for spring; On the other hand, green is regarded as a symbol of spring, praising the beauty of spring, life and life.