This hat is knit from the top down using a method found on knitty.com. A link to the method is in the pattern.
The hat is made to fit an adult size head, with no real gauge. If it feels like it might be to large remove an increase row.
I used left over stash yarn. Acrylic, worsted weight. It was pretty stretchy yarn so keep that in mind.
I would say no more than 150 yards for each color depending on your knitting style. (keep in mind I did use scrap yarn so this is an estimate)