I’m adding these notes long after I started so I can’t remember what size I knitted.
I did a few extra rows of colour 2 on the body so the colour change would sit under my bust not on it. Then adjusted the colour change on the sleeves to match.

I knit the first sleeve and it was too wide which is unusual for me as I don’t have skinny arms.
So I ripped it back and knit them decreasing every 8 rows instead of every 10 initially then every 6 rows on the lower arm. Decreased 2 stitches at the beginning of the wrist rib.

For the neckband I picked up slightly less stitches than it says down the side of the neckline. Used 3.25mm needles for the neck rib (as opposed to 4mm for the rest). Knit 7 rows taking a couple of knit 2 tog decreases at the shoulder seams.
I thought that would stop the neckline sticking out but the first time I cast off it still stuck out. So I undid it and cast off again taking some decreases in the cast off row (always with the knit stitch ladder on top of the purl).
ie k2tog at each shoulder seam, 6 x k2tog spaced out around the front, 4 x k2tog spaced across the back. And it sits perfectly! I used the cast off where you knit two stitches together by putting the left needle into the 2 stitches on the right needle, it gives a nice stretchy finish for a neckline.
So pleased with this jumper!