How does Richard Wright use imagery in The Man Who Lived Underground?

Through the many episodes of "The Man Who Lived Underground," Wright weaves imagery of light and darkness, repeating, reinforcing, and inverting the Imagery to heighten the sense that the world is chaotic and ultimately unknowable. For the most part, the underground is the world of darkness, and the world above ground is the world of light. The faint light that there is underground is strangely colored, from the "lances of hazy violet" coming through the holes in the manhole cover, to the light from the man's matches, "glowing greenishly, turning red, orange, then yellow," to the "red darkness" of the furnace room, and to the "yellow stems" from another manhole that reveal the floating baby. These odd colors heighten the nightmarish quality of life underground, but also highlight the fact that in this place the man is learning a new way to see.