it so depends on the look you want. If you want the quilting to blend into the top, use brown on sashing and triangles and an off white in the squares. If you have a pattern you want to highlight, use a brown or light brown in the white squares. You could use an off white or beige to do a scroll pattern in the sashing. I personally would not because I would prefer the focus be on those great looking blocks. I know this sounds like a lot of wishy washy advice, but the bottom line is what do you want to do? what do you want to highlight? or blend in?