This happened to me recently, I found the absolute perfect backing fabric for my latest quilt at my LQS, it was a really, really pretty dark teal blue batik. I bought the rest of the bolt, which was about half of what I needed, then went online and bought more. I am well aware of differences in dye lots, but I hoped that since it was a batik and the dyes are different throughout the yardage that it wouldn't be noticeable. NOPE. When it arrived, it was a completely different shade of blue and was muddy, not pretty at all.