This is a top-down yoked tee/sweater, most of it worked in stranded colorwork. It starts at the collar with corrugated ribbing, then some short-rows for neck shaping and then the full yoke. After sleeve separation the body is worked mostly in stranded colorwork and then finished by twisted rib. Sleeves are short (to the elbow) and they are also finished by twisted rib. 

For maximum effect the fire pattern contrast yarn should be self-striping, like Zauberball Crazy. I used two different background colors but using only one is ok too. Garment fit is fairly close to the body with just a slight positive ease. 

Yardage:
MC blue: 46%
CC1 fire: 32%
CC2 teal: 22%
See screenshot of size table for more detailed numbers.
A word of warning: test knitter yardages have varied wildly, so make sure you have extra yarn, especially if you are a loose knitter.

Testers rated pattern difficulty 4/10 and pattern clarity 9/10.