How does Langston Hughes use imagery in Mulatto?

The Southern evening is filled with stars. On the sweet Earth, “dusk dark” women’s bodies give birth to these “little yellow” bastard boys. The stars and the scent of pines are everywhere. It is a “nigger night, A nigger joy," the speaker says, and ends the poem by repeating that he is the white man’s son, "a little yellow bastard boy."