I feel like a pattern that does well with Civil War reproduction fabrics would do well with these as well. Similar colors and level of busy-ness. This blog post has a lot of interesting options.
Amish quilts use solids, but they often have deep colors like this. Maybe a book of Amish Quilts like this one will spark something.
You can also see if the manufacturer has a quilt pattern that accompanies the line. Usually I will go with something I choose on my own, but sometimes they really do get it spot on! Not sure who makes these.