This is two colored fair isle knitting (usually fair isle knitting refers to multiple colors). I modified a Norwegian star pattern to make these matching hat and mittens.
I completely made these up as I went along following another sock pattern to make the heel and toe. I made 2 other pairs of fair isle socks in different colors and with different patterns, once again made up as I went along.
This sweater is not completely fair isle. The part that is fair isle is the row of purple sailboats at the top.