General Wives Quilt - Ready for Quilting

I have been finished with the quilt top for over five months.  I have been hesitant because of my old sewing machine.  It acts up and I become frustrated and don't finish putting the backing together to fit the quilt top.  Since I have my new machine, I thought I had better get the backing done and call a quilter to finish it for me.  It is large, 92.5"x92.5" and the pattern calls for the backing to be 100"x100."  I purchased the backing quite a while ago and am ready to tackle the large backing piece.

This fabric (left) is the back.  You can see it in the picture of the whole quilt below.  The picture on the right does not give the true color of the fabric.  In the picture on the right, it is yellow.  I don't know how to fix that.