Three yarns total, working two strands at a time to create a subtle color-shifting design. I'm not being very particular about how many rows are each color. Using a basic seed stitch. I'm using Pattons Classic Wool Merino in Natural Mix, Winter White and Natural Marl. (The marl is 3-ply mix of white and tan, which helps make the transitions a little smoother.) See the finished scarf here.