As the central color theme of each book in the trilogy is green, blue, and red respectively, there are many moments in which red is used to foreshadow events to come in the final book, Reached. For example, Cassia learns that Xander's favorite color is red and not green, hinting at the greater role he will come to play. Ky also paints Cassia wearing a red dress on a cave wall in Chapter 44, symbolizing the conclusion of her character transformation from unassuming Society member to Rising rebel.
Cassia’s statement that “it will all come clean” (337) in Chapter 48 can be interpreted as a larger foreshadowing of Crossed’s final chapters when she, Indie, and Ky join the Rising, as well as the trilogy’s final book, where the country may be washed clean of the Society, a metaphor that compares the totalitarian government to filth in need of removal.
Finally, the book concludes with a foreshadowing from Cassia, who observes that the natural beauty of the frost will "too soon vanish" (376). This could be interpreted one of several ways. The chill of the frost disappearing could represent the cold grip of the Society loosening as the Rising takes it down. The beauty of the frost dying could also symbolize great loss to come. In either case, the statement hints at impending change, reinforcing the cliffhanger on which Condie leaves the reader before the events of the trilogy's final book unfold.