'I know for sure that I have an instinct for color, and painting is in the very marrow of my bones' The life of Van Gogh has gone down in legend as the archetypal artist's existence. He was irascible and short-tempered, hugely passionate and emotional, absurdly talented and, for most of his lifetime, notoriously misunderstood and under-appreciated. And yet today, we see him as one of the most inventive, influential and admired...