It would help if I knew what book it was but I'm since I don't I am going to go with the fact that it is foreshadowing. Say yellow means happy as the sun well. We have the Yellow wallpaper yes. Say the yellow wallpaper starts to fade and pill that is the foreshadowing.
An infinitive is the word "to" plus a verb so if you see that in a sentence its probably an.infinitive (I'll give an example below)
Ex: Renee suprised her sister to scare her.
-The infinitive would be "to scare" because it could be mistaken as a verb but the actual verb is "surprised"
Hope that helped!
A diagram because people will be able to visualize the exact steps taken
