Hong Kong is silver – a silver dollar by the sea. Singapore is jungle green (creepers would overcome the deserted city in a few years), and grey for the heavy rain clouds that gather in the afternoons. Seen from the air, Mumbai is blue, the blue of the ubiquitous tarpaulins which waterproof its slums. New York is dark brown and black in tall vertical shafts; no wonder it looks so pretty in the snow. Harare is the purple of its jacarandas. Paris is beige and wet slate grey. Jo’burg shines like a seam of coal. Edinburgh is black and green plaid, and greasy with rain and the yellow daubs of the the street lights. Trieste is Adriatic blue and limestone. Venice is a mirror reflecting the lagoon sky and the moods of its tourists, which vary from season to season. And London is red and green and portland grey and many colours in between – I know this city too well to generalise.