Sashing Stash Cottons
(Click on a swatch to see an enlarged image.)
Coordinated Solids from Riley Blake
Alternate Matching Solids from Robert Kaufman Kona Cottons
Because ink colors can differ from one print run to another, if it is important to your design choice that the Sashing Stash print match a solid, I recommend checking out Kona Cottons. The latest Robert Kaufman Kona Cotton Color Card now has 303 color swatches. (This card from www.robertkaufman.com is a handy investment, useful for all kinds of projects.)
Currently, the Kona Cotton Solids colors that most closely match the colors of Sashing Stash are: