I'm not sure that half-and-half color tablecloths would give you the effect you want. You might be able to find some inexpensive fabric, contact paper, or even giftwrap printed with a patchwork pattern. If you are good at crafts or know someone who is, maybe you could sponge-print white tablecloths to look like patchwork? Or just do some sort of centerpiece with loose patches, colorful spools of thread, pincushions, scissors, tape measures, etc.?

Why don't you just go to a fabric store (Check Walmart's fabric dept, if you want to do this on a budget), and buy fabric that's printed to look like patchwork. There are loads and loads of printed 'quilt' fabrics out there. You could get different patterns/colors for each table, or you could get all the same. I think different, but coordinating patterns would be striking and fun. You can just turn the raw edges under and stitch--by hand or machine, or if that's beyond your abilities, just cut with pinking shears and leave them be. And just think, when the party is over, you could give her the fabrics--any quilter would be delighted to have yards and yards of extra fabric to incorporate into her projects.

If you do happen to find people willing to lend you quilts for the tables, be sure to buy some heavy duty clear plastic to put over them to protect them from food spills (again, you can get that in the WM fab. dept. It's on a roll, right near the cutting desk, usually).

Thanks for the ideals. It's a big help...