Originally Posted by QuiltE
More thoughts, please ......
With the smaller squares, do you think a double colour sash and corner posting would be too much? Or KISS and go for a single?
Dunster, you suggested white ... what about a soft yellow that goes with the fabric? Or too close and would lose the kaleidoscopes?
The only reason I suggested white was that I was thinking of trellises. There's no reason it wouldn't be lovely with yellow. Sometimes it makes the pattern seem to float if the sashing blends in with it. That can be lovely. Audition some yellow and see whether that's the look you like best. If you post 5 different sashings you will surely get 5 different responses (or more).