This is a great way to use that funky handspun yarn you picked up somewhere!
-The main colour could really be any sort of plain chunky yarn.

You need 4 (4, 4, 5, 5, 6) skeins of Malabrigo Worsted for the main colour and about 72 m/ 78 yds of any “art yarn” style super bulky for the contrast colour yarn at yoke.

This sweater is knit in pieces first, flat. Then you join the pieces and knit in rounds of rib for the yoke.
If you had lots of art yarn you could knit the yoke further, into a cowl.