On her travels she visited remote Central American villages where women still wear skirts dyed with the purple tears of sea snails; learned how George Washington obsessed about his green dining room while he should have been busy with matters of state; and investigated the mystery of Indian Yellow paint, said to have been made from the urine of Indian cows force-fed with mango leaves.
From mascara to nomadic carpets and pillar boxes, the story of colour is the story of the efforts of artists and artisans to reproduce the rainbow - and the impact their work has had on the world.