Abstract: Perceptions of colour cannot be trusted. This is something I know because I'm colour blind. Being colour blind means I'm mostly bored by the sunsets that other people enjoy (their vivid pinks just look like greys to me) and I'm also sceptical about the need for exactitude when naming what colour it is that one sees. No wonder the works of Vincent van Gogh first stood out to me. Here was an artist who used colour not to reproduce reality but, remarkably for the 1880s, as a conceptual tool, unafraid to use something like cerulean blue to render a corn field, every tone a metaphor for a particular life force ("What colour is in painting, enthusiasm is in life," he wrote to Theo in 1886). Against the unstructured inclinations of his Impressionist peers, colour in a van Gogh painting is always in dialogue with his rigid, drawing-like forms, waging his own very different battle with the chromophobic tendencies of Western art, which, at least since the time of Aristotle, equated colourful extravagances with modes of vulgar, feminine, Orientalist, primitive or infantile excess.