If you can't get a match from the mfgr. And my guess is that it's gonna be tough, as these fabrics, like paints, and other things, are made in "lots", so there will be slight differences between one batch and another.
I'd recommend going for a solid or plaid that will compliment the fabrics you have, but not exactly match them. If you have a plaid fabric now, go for a solid that matches one of the colors....if it's a solid, go with a plaid that has some of that color in it.
It should be a lot easier, and cheaper to go that route.
Good luck:)
