This picture shows the seams when I lay the sets flat the right seam is an 1/8" off. I have the left set of seams butted up exactly the way it would be sewn.
Here is the pink, blue, pink set under the ruler. It only measures 3 3/8" it should be exactly 3 1/2".
This is the blue, pink, blue set. If you look at the 3 1/2" mark you can just see the color difference between the background and the blue piece of fabric. The important thing is that it is exactly 3 1/2" long and the center strip is exactly 1".