I’m not sure how clearly it comes out in the photos. However, I reversed the colour patterning midway through the top, so that colour A (brown) became colour B (teal) and vice versa. This was borne out of practical necessity because otherwise I was going to end up running out of the brown!
Partway through the back as well, which introduces colour D (the mystery colour).
I’m really enjoying knitting this one. The various patterns will keep it from becoming boring, I think!