Writing background: I guess this poem was written between 1970 and 1990. At that time, China was experiencing the reform and opening up from the Cultural Revolution to the planned economy.
Writing metaphor: the dark blue background is obviously the author's melancholy about the social status quo; Oranges, metaphorically speaking, want to keep a calm heart, but deep down they still can't restrain their desire to contribute to society.
The whole poem uses metaphors, and through the description of still life and the surrounding environment of still life, it expresses its love for society and worries about the development of the social motherland, and is ready to contribute its own strength to society!