From the 2021 book:

Materials
Yarn
Knitted in a mohair–wool-blend yarn with approx 75-per-cent-mohair content and 100m/50g in 10 colours as folls:
The sample garment is knitted in Wool and the Gang’s Take Care Mohair, with Black as the main colour and Punk Pink, Misty Mauve, Lipstick Red, Deep Grey, Tangerine Dream, Powder Green, Cinnamon Dust, Blue Steel and Midnight Blue as contrast colours.
Many different colour combinations can be devised—if fewer colours are used then more of each colour will be needed.
Main colour (MC): 5 × 50g balls
Contrast colours (C): 1 × 50g ball each of 9 colours, for colourwork triangles

Recommended needles and accessories
Two pairs of needles are required: one pair of the size to give the correct tension, for main parts, and one pair of one size smaller, for ribbing.
1 pair 5mm (UK 6, US 8) needles for main parts
1 pair 4.5mm (UK 7, US 7) needles for ribbing
2 stitch holders
For making ridges, use one of the 4.5mm (smaller) needles or an even smaller size, as preferred