However people have frequently asked me what the red is, which makes me think I should start over.
Spoiler warning? Highlight below to read;
The cover is meant to be representative of the girl that Harold meets who works in the garage. She notably wears a red tabard, an apron-like garment. This character is the catalyst of the story in that she gives Harold the idea of his pilgrimage, hence the word 'Pilgrimage' being inside a speech bubble.