Originally Posted by sushi
If I were you, I'd use one color as a narrow sash (finished width 1/2" or less) and the other as the wider sash that you've already planned. I don't think it'll matter which color is used for which purpose, but I'm sure the overall effect will be much more stunning than anything you can achieve using only one fabric.
Just my humble opinion, of course.
Love this idea but I would use the blue as the sash closest to the blocks - makes them "pop" to me. just my 2 cents