When I was younger I always preferred high contrast to low, and usually chose bright white over off-white when non-colors were needed. As I got older low contrast colors that melted into each other began to draw my eye and I felt more comfortable with cream, ecru, gray and other off-whites. I attribute the change to a growing recognition and appreciation of shading and variation of all kinds. I used to like everything to be very clear, and now I know that mostly they aren't. At any rate, most of the dishes I have collected over the years are off-white and I always use off-white cloth as a basis for my textiles even when I have to dye white cloth to get it that way. Now that I am working with Lynne's dishes, I need to consider what non-color I should start with, and it turns out to be kind of tricky. Against the ecru lace runner her saucer looks very white, but against true white it looks creamier, especially with the gold banding. It isn't necessary to match exactly, but I don't want to fight with the basic tone of the dishes as I consider what to put with them. Subtle variation is one of the most fascinating things about using color and since adjacent colors change each other it is often surprising how they look together.
Since I favor runners and square tablecloths I often need an undercloth. I originally thought that I would just buy one off-white cloth and layer the colored things I made over it to change the look of the table. That actually worked pretty well, although my interest has led to an accumulation of other colors too for dishes, tablecoths and napkins. I would still recommend starting out with a white or off-white cloth that fits your table with a generous overhang. Then you can add any sort and shape of textile you want on top of it for color and variation. It may be the only one you need.