Yarn:
6 x 50g balls of yarn in main colour, and
1 x 50g ball of yarn in three contrasting colours.

Additional items:
6 buttons
41cm square cushion paid
Stitch markers.

From the pattern description:

Knitted in a cotton yarn, this colourful garter-stitch stripes of this striking cushion stand out against its white stocking stitch background.

Background fabric is easy stocking stitch, while stripes are worked in garter stitch.