This question seems to be an essay question that your teacher has asked you to respond to; I can help to give you some ideas, and I hope that you can use them to spark your own opinions and examples to use in an essay that you write yourself.
Color, in "The Book Thief" is used by the narrator, Death, to describe the skies and souls in the moments that he comes to take people's spirits away. It is also, as Death states a couple pages in, a "distraction..vacation...in colors." It is a way of distracting him from his awful job; he notices the colors of the day around him, and of the souls that he takes. It is highly symbolic; on peaceful days, the skies are blue. On awful days of war and destruction, the skies are blood-red and the color of fire and smoke. The colors represent either the events of the world or area at that time, or, the personality and temperment of the soul that Death is taking. For excellent quotes to use for your essay, look to the first few pages of the book, where Death describes some of the significance of colors.
The first specific reference to a color coordinating with an event is white, where Death comes for Liesel's brother. It is white because it is winter, and there is snow everywhere, a "blinding kind" of white. Here, color represents both the environment that death has come to, and, a second function, a distraction for him. He mentions,
"I studied the blinding, white-snow sky...I practically inhaled it, but still, I wavered. I buckled--I became interested."
The scene of Liesel and her mother grieving piqued his interest, and he tries desparately to distract himself with the color white around him, but fails, and sticks around a while to learn more. So in this quote, a few pages into the novel, we see color used as both a descriptor of environment, AND a distraction for death. For other great examples, look to the beginnings and endings of the chapters--this is most often where Death steps in and talks about colors. You'll find good examples there.
To describe how color impacts you as a reader, think about what images each color that you use in your examples conjures up in your mind. What feelings or images come to mind with each color mentioned, and how does that add to the emotional impact of the example itself?
I hope that these thoughts can help to get you started; good luck!
The novel, The Book Thief, is narrated by a personified “death”. Death is made out to have all the same feelings as humans and talks about how he wishes he could take a vacation or at least a break from his job, but there is no one to take his place. In order to distract himself from the surviving humans that bug him so much he takes note of the colors that surround the humans when he takes their lives.
The first line the narrator tells us is, “First the colors,” alluding to the fact that colors are extremely important to him. He then goes on to tell us that pointing out the colors makes his job less stressful and helps him relax. Death says he likes dark chocolate-colored skies and that they suit him, symbolizing the darkness of death itself. At the beginning of the next chapter he uses a whole paragraph to talk about the color white. He specifies that it is a “blinding” white, which is thought of as most pure. The scene he is describing is when Liesel’s brother was being buried and as a child he was pure.
Later in the story when Liesel meets her new family, the narrator takes the time to describe Hans Hubermann’s eyes as being silver and Liesel understanding that he was “worth a lot.” The color silver symbolizes security, reliability, and also calm, three things that Liesel found in Hans. Death then tells how Liesel’s favorite key Hans would play on the accordion was the silver one. Ironically, Hans was a painter and worked with colors as his profession.