The narrator, Death, is an interesting fellow. Many times when he is about to pick up a soul, he describes what the sky looks like at that exact moment in time. Since Death picks up many different souls during the course of the story, he describes many different scenes; therefore, each death scene has a different color or description associated with it. For example, Death's first description of the sky at a scene of a bombing is as follows:
"The last time I saw her was red. The sky was like soup, boiling and stirring. In some places, it was burned. There were black crumbs, and pepper, streaked across the redness" (12).
The above passage mentions the color red, twice. Other words associated with this scene of air-raid bombings are boiling, stirring, burned, pepper, and streaks. These images also make one think of fire, flack, and debris. Other than the redness, there are no other colors mentioned explicitly, but they all mean "death."
Another time the Narrator describes the sky is at Johan Hermann's death, as follows:
"Oh, yes, I definitely remember him. The sky was murky and deep like quicksand. There was a young man parceled up on barbed wire, like a giant crown of thorns. I untangled him and carried him out" (145).
In this passage, there aren't any specific colors mentioned, but the word "quicksand" suggests a particular image that might carry with it a dark, blackish hue--or any color which one associates with it. On cue, though, Death describes the sky again as if it were the victim's last sight he witnessed before he died.
Below is one last example of Death describing the sky as he is collecting Jewish souls:
"Summer came. For the book thief, everything was going nicely. For me, the sky was the color of Jews . . . All of them were light, like the cases of empty walnuts. Smoky sky in those places. The smell like a stove, but still so cold" (349).
This description brings up Death's experience during the first day that Auschwitz (concentration camp) started burning bodies. The color of smoke can be many shades of black and white and gray. This must be what he saw when collecting these souls. The profound contrasting images of a hot stove also being cold drives home the senselessness of these innocent people's deaths--as if he is shocked to witness the coldness behind the Nazis indifference to murder.