Battle Axe, it's great that you have a neighbor who could offer some input. When I first looked at your picture, I didn't even register the sashing pieces as part of the quilt. I think my brain figured they were part of another project ( I often have a mish-mash on my design wall). Sounds like your switch will do the trick (although I don't envy you re-making all those tri-rec blocks).
Thanks everyone for the wonderful comments. I was a bit disappointed in myself for sticking with Bonnie's colours this year but it was what I had in my stash, and I do love the final result.