I’m adding stripes by swapping between the 2 yarns every 8 rows and just carrying the other yarn up the inside, twisting it in every second row. Sizing turned out well with 5ply yarn (instead of 4ply), but the ribbed brim is a bit floppy. I should have sized-down on needles for that part.

50% Nylon, 25% Acrylic, 25% Wool
Wash: 30°C
No iron, no dryer. Dry clean symbol P.