I remember my first working winter in New Zealand. I took the train to the city from Henderson and as it sped down the track, I would spy spots of colour in an otherwise wall of black- everyone was in black. It seems apt as Kiwis stubbornly cling to the belief that the only acceptable weather is warm, sunny and summery; anything that is opposite is an anomaly, an outrage like disliking Marmite or betting against the All Blacks.
Some have budged from the winter uniform since then but black, like anything quintessentially Kiwi (most of the current national sports groups have the word 'black' in their names after all), will never go out of style.