2.25 needles for main body
3.25 needles for colourwork
2.0 needles for ribbing
2.75 mm needles for sleeves (to maintain the same tension as body as I tend to knit the sleeves tighter)

Modifications:

• extra length added to yoke
• an additional stripe section added to body before colourwork
• full length sleeves (extra stripes added)
• the original design features wider sleeves. For a closer fit, I started the sleeves with 76 sts (collected all sts I could around the armpit to avoid holes, and in the next row reduced to 76); knit 20 rds without reduction, and then reduced 2 sts every 10 rounds 10 times (reduction method: when 3 sts are left till BOR, ssk, k1, slip BOR; k1, k2tog)
• body: last two rows knitted with contrast colours to match the beginning of the sweater (collar)

Note that the collar of this design is closely fitted.