Now, I'm going to go a bit off the color matching idea...have you thought that if you buy solids, any grease or other stain will show immediately and may not come out without special treatment? You might try for a print that has some of the Fiesta ware colors and use that as one side of the placemats. That way, if they do get stained, the print side can be used and the stain won't show as much. I bought a Kona color card years ago and haven't regretted that purchase.