Pattern uses fair isle/waistcoat/split sc st. Chart and pattern could also be worked up in single crochet, omitting the waistcoat stitch completely. Single crochet might give it a slight lean to the pattern since it is worked in the round.

I used Red Heart Super Saver and both mittens and hat used half a skein of black, 1/4 skein of hunter green and minimal of grey heather