This all looks so familiar as I have made several quilts and wall hangings from my husband's shirts that resemble yours. I love the design you have chosen. The background/sashing I have used in the projects I've done is between the 2 that you are proposing and I like it. I find white to be stark but the "tan" you show is a bit "too". I'm currently using one that is ecru with just a bit of a darker shade in it--almost like a tie-dye tea-dye?? It is a good blender. I'm suggesting something more like the color that I see to the right of the picture with the white sashing only a bit lighter!