
"For almost five millennia, indigo - a blue pigment obtained from the small green leaf of a parasitic shrub - has been at the centre of turbulent human encounters, prized by slave traders, religious figures and the fashion world.

"Indigo: In Search of the Colour That Seduced the World
by Catherine McKinley is the story of this precious dye and its ancient heritage: its relationship to slavery as the 'hidden half' of the transatlantic slave trade, its profound influence on fashion, and its spiritual significance, which is little recognised but no less alive today. It is a richly told story, brimming with electrifying tales of those who shaped the course of colonial history and world economy."

Victoria Finlay, whose Colour: Travels Through the Paintbox
I strongly recommend, says of Indigo, "A charming book: ethereal, wise, personal, as well as an imaginative exploration of what this colour really might be, when you go under the surface of its just being about blue".
(Book of the day - once upon a time ... is here).