I'm pinning this for inspiration even though there isn't a pattern given for this. Link takes you to ravelry lorijo's fair isle cardigan. She used unknown sweater pattern, fair isle pattern from some mitts, and colors inspired by a painting.
foggy maren cardigan on craftsy. Also on Ravelry called Top-Down Icelandic Sweater by Ragga Eiríksdóttir. Designer Ragga Eiríksdóttir teaches you how to knit a fun, authentic Icelandic sweater from the top down and in the round.