Cast on 88 sts+1 for invisible joining in the roundwith 5.0 mm needles (c/on long tail, alternating 1k,1p) and red yarn held double.

Brim: (8 rnds)
1st round: (k4,p1,k2,p1,k2,p1)x8 = 88 sts
Worked for a total of 8 rnds, including the c/on rnd, in red yarn.

Body: (34 rnds)
Change to: (k4, p1, k5, p1)x 8 times and worked for another 8 rounds, in red yarn.
Change to kaki yarn and work in pattern for 6 rnds; then 2 rnds red, 6 dark green, 2 red, 6 kaki and 4 red, before starting dec’s. Since I had instances with just 2 rnds in same colour, I used this jogless technique to avoid changing the colours in the same spot. (I could’ve made probably another one or two rounds in red before decreasing.)

Decreases: (15 rnds)
As per pattern, for size medium.
My preferred p2tog tbl is the second method in the video.

Note
Used 5 ply yarn held double throughout, for all colours.
Followed the measurements for medium size as per pattern.