Solid white was definitely used in CW quilts. The best example is the Jane Stickle quilt better known as Dear Jane. I can't say for sure if the original fabric used was white or more of an eggshell or if it was white that dulled or got stained over time. I've seen the quilt in person and it is amazing but it has been a couple of years so I can't be sure. I believe the write up on the display mentioned it was thought Jane had a relative in the textile business and that is how she had access to such a wide array of scraps.
Here is a link to a close up of the signature corner of the quilt from the Bennington Museum
https://benningtonmuseum.org/2014sit...b-1000x986.jpg
and here is the link to the museum write up about the quilt with another picture of the whole quilt.
https://benningtonmuseum.org/portfol...stickle-quilt/
The light value shirtings with tiny little designs look nice as previously suggested and illustrated by Teen's lovely quilt. But as the DJ quilt illustrates, a solid works just as well and is still in keeping with what was done in that time. I think a nice eggshell color like Moda Bella Solids color snow or Kona Oyster (which has a kind of grayish undertone) or Bone or even an unbleached muslin would set off those CW prints very nicely