I got to cutting my darks - and realized I'd calculated for all squares, and only needed half in the dark!
I had figured I'd need about 36 strips total, and I'd already cut 20 . . . so I wasn't too far away from the 18 that would be for the dark. I've got the 18 lights cut now. Next step is to cut them down into smaller strips so I can do more mixing before I sew two together.