This article explores the genesis of the apparently disparate fields of colour psychology, chromotherapy, and colour forecasting. They came to the fore during the 20th century, and while ostensibly unrelated, their common ancestry lies in the late 18th and 19th centuries. This period witnessed the discovery of such strange forces as magnetism, electricity, X-rays, and radio wavesin addition to odic forces and the colour aura. These were all invisible, mysterious, and to the public and many prominent scientists, equally plausible. This article traces a major influence back to spiritualism and Theosophy: both privileged colour and attributed powerful influences to it. This legacy remains, though not in the scientific domain. (c) 2013 Wiley Periodicals, Inc. Col Res Appl, 40, 99-106, 2015