Cut strips of whatever colors you want and strips of background whatever width you like. Sew them together alternating color/white then press seams and cut strips from this as wide as your original strips (if you want them square). then sew these strips together end to end so you have a long strip of color/white, then sew your background strips to each side of this. I took a photo of this process but can't figure out how to post a photo in a reply!