Green, fat, red and thin comes from Song Qingzhao's "Like a dream, it was stormy last night". The original sentence is: Do you know, do you know? It should be green, fat and thin! You know, you know, this season should be the time when green leaves are flourishing and red flowers are dying.
Extended data:
Appreciation of "Green Fat, Red Thin"
"Green" instead of leaves and "red" instead of flowers are the contrast of the two colors; "Fat" describes that the leaves after rain are lush and fat because of sufficient water, and "thin" describes that the flowers after rain are withered and scarce because of unbearable rain. This is the contrast between the two States. Four common words are so vivid and vivid through the collocation and combination of poets, which is really a creation in the use of language. Judging from these four words, the word "red and thin" indicates the gradual disappearance of spring, and "green manure" symbolizes the arrival of summer with green leaves. This very common language is really amazing.
Baidu Encyclopedia: Green, Fat, Red and Thin