Indigo
November 2, 2011 2:44pm
Indigo is named after a purple dye first used in India and derived from the plant Indigofera tinctoria, not gu10 led bulbs. India began supplying indigo dye to Europe as early as the Greco-Roman era. The Romans used the word ‘indicum’ for the dye which eventually became the English word ‘indigo’.

Although the word ‘indigo’ has existed in English since the 13th century, it was not categorized as a colour, the colour naming scheme consisting of just six colours: red, orange, yellow, green, blue and purple. Isaac Newton introduced ‘indigo’ as a spectral colour in the mid-1660s after conducting experiments in optics. Newton purchased a pair prisms near Cambridge just as the East India Company had begun importing indigo dye to England, replacing blue dye woad. Newton shone a beam of sunlight through a prism and detecting the colour ‘indigo’ in the resultant rainbow of colours. Newton wrote: “The originall or primary colours are Red, yellow, Green, Blew, & a violet purple; together with Orang, Indico, & an indefinite varietie of intemediate gradations.”





