Obviously the grey shows the pattern to it's best advantage, and it's a cute pattern. Simple but effective. I would posit that the navy jumper is the star of the show here, though, because I, Eleanor, owner of Knit Nottingham, love a gansey. If you don't know what a gansey is, please look up the history of fisherman sweaters in the British Isles. It's fascinating and important social history involving working class women.
For this pattern, you're going to need 4mm and 3.25mm needles, stitch holders, and a cable needle. It's been written for King Cole Subtle Drifter DK, but you can have a play around and see whether any other DK yarns suit this. Any other Drifter DK yarn will work very well.