The design starts with an i-cord from which stitches are picked up. Initially you will work back and forth in rows, until you join to knit in the round when the Henley slip is done.
This is a plain stocking-stitch pattern. As such it lends itself to variegated yarns or stripes in different colours.
As this is a Measure & Make pattern, I cannot predict your yarn requirements. Don’t see this as a drawback; see it as an opportunity to play and add whatever yarn and colour you feel like, when you feel like it. Rebel with me.