If you enjoy that sort of thing, I can also recommend Scrap Republic by Emily Cier which is full of inspiration. Her Volume quilt was the starting point for this quilt. My version is larger, at 60 x 80.
I also incorporated neutral blocks. I always seem to have lots of these low volume strips, which can be hard to use up. I think they provide restful bookends to the quilt.
I used a simple figure eight, free motion quilting design in each column, moving from side to side, starting at the top of the quilt and going down each column to the bottom of the quilt. The side to side movement was hard to achieve fluidly with my tiny machine's throat space because the columns are 5 inches wide, but it was doable. I think it would be far easier with narrower columns, and I will certainly try it again. It went so quickly.
The black and white striped binding is a great choice for any rainbow quilt.
Amazingly, I still have plenty of scraps. I'm contemplating some more therapeutic sewing: maybe a baby quilt with a more limited palette.