I had this problem once. I went back to the store and bought more of what i thought was the same fabric. It turned out to be a slightly different color. Different "dye lot" I suppose. I was extremely upset but ended up using two strips of the new fabric on the sides of the backing. Very painful at the time but now it's one of my favorite backings. It's interesting to throw in a little variation in the back. I may do it again on purpose!