They are the same. This quilt is such an optical illusion! ALL of the unpieced squares are the same fabric. They kind of fade into the background on the picture in the PDF file as some are framed with the darker fabric..and some AREN"T framed. The unframed ones can look different, but trust me, in this pictures they are the same. I have that issue.
That being said, you CAN change those fabrics. I just saw a post that asked if they could use this pattern as an I Spy. Brilliant!