What does the color 'yellow' symbolize in Elli's life as recorded in the memoir, I Have Lived a Thousand Years: Growing Up in the Holocaust?

Elli has a new bicycle that is yellow, and she also wears the yellow Star of David to show her Jewish background. The color yellow symbolizes her changing world. Guards force Elli to give up her bicycle and to wear the yellow star. Thus, the color yellow, normally a bright color related to the sun, brings fear and doubt to Elli and her world.