In "What dreams may come", blue flowers are ubiquitous. What do they represent?
Annie's grief (at the loss of their children) made substantive as Chris walks through her paintings
When Chris (Robin Williams) dies he finds himself in an afterlife that emulates his wife Annie’s work: She restored nineteenth century paintings, and in her spare time painted pictures which reflect elements of their life together. Now Chris finds himself walking within her living paintings.
Chris' grief at the loss of his family when Annie left him (and obviously their subsequent deaths)
"And I always imagined Chris, the last time he saw his children, standing there with the van going away, under these trees and the whole street covered in leaves, in these blue Jacaranda leaves. And, every time he would think of his children, from then on, through the rest of the movie, somewhere in that shot would be a color that was Jacaranda purple."