Waves off Kanagawa came from me going through a colourwork phase and an ombre palette phase at the same time. This was made using a pack of mini-skeins but you could likely get the same effect using a yarn with a long colour repeat.

I’ve done this as a baby sized hat, but it should be easy to size up. I’ve highlighted the pattern repeat in red on the chart. Each pattern repeat added horizontally will add approximately 3cm to the width of the hat. Each pattern repeat added vertically will add approximately 2cm to the height of the hat.

Increase the rib in line with your preferences - for my own hats I generally do 20 rows of rib. For the crown, you generally want to get to less than 10 stitches before you break the yarn and run it through. Add extra rows of k2tog across all stitches, until you get down to 10 stitches or less.