Red is a colour with a distinct history. Throughout the centuries, it was favoured for its chromatic appeal and for its pre-dominance over other colours. For millennia, wearing red clothes expressed the legitimation of social status, political authority, religious rank, and cultural identity. Since ancient times human beings have tried to find dyestuffs that could reproduce the powerful tint of blood, fire, and flowers. However, it’s not always pretty - ingredients include rancid castor oil, sheep’s dung, bullocks blood and urine. In this episode we ask why red is the hottest colour. We uncover the roots of ancient colourants and discover how today’s designers are taking advantage of they’re their inherent qualities. We talk to a Zapotec weaver from Mexico about cochineal, a Dutch design duo who are finding new ways with natural dyes and an Ajrak printer who reminds us of the long history of madder in the Khatri community in Gujarat.