Even though it looks complicated, it’s easy to make a slip stitch hat.
you will be combining a stitch pattern with stripes of color. The stitch pattern is a four row repeat and the color is changed every other row.
Coldwater Collaborative has Color Design Packs with the right amount of yarn to make the hat available at their shop. 5 colors are needed to make the hat. Only about 35 yards of each color are needed.
There is also a similar pattern for Baby hat & mittens.