I played some more, there are about a dozen of these done now. I have had to order more oranges to play with the other blue blocks and explore curves.
I decided against black and white to go with this as I found this busy blue fabric for the smaller block pieces in the stash. Perfect.
At the weekend I hope to be able to piece a couple of 12" blocks in blue and white, with the larger components cut from the blocks above and the smaller components cut from the blue fabric opposite, all on the white background.