I agree with bearisgray's comments.
I use Warm and White if the quilt has larger white chunks in it and when possible I will press to the dark. If I am nesting seams and press to the light, I will often trim the dark seam allowance by a "smidge" so that it does not show.
My only thought/concern about two layers is that, depending on the block, your seam intersections could be too bulky.