Indigo is a colour on the visible spectrum, in-between blue and violet, on the seven colours of rainbow. Recognized better when called “deeper than blue”.
Isaac Asimov wrote in the 1970s, “It has never seemed to me that indigo is worth the dignity of being considered a separate colour. To my eyes it seems merely deep blue.” Isaac Newton’s breakup of the visible spectrum included a blue-purple colour called indigo. But indigo was later stripped off of its status of being a colour when Goethe proposed a symmetric colour wheel of 6 colours, which contained no indigo colour. This debate is still going on as universities and scientists are trying to find an answer of this question… Is indigo an independent colour or just a deeper blue?
The king of blues until the early 20th century, the only blue, and even today the only natural blue that withstands any considerable amount of time is indigo. This dye is being used dating back as far as 2000 BC, found in mummies’ tombs in Egypt. Though India is believed to be the oldest centre of indigo dyeing in the world as it exported indigo to Europe as early as the Greco-Roman era.
Indigo cultivation is thought to have existed in the Indus valley for more than 5,000 years ago.
Even the name suggests where the colour historically came from. The word is derived from a Greek term that means “from India”.
Indigo is a plant-based dye derived primarily from the plant Indigofera tinctoria, a tropical plant that was cultivated and became a staple agricultural crop.
It is a natural dye which requires no chemicals at all and thus, is the most obvious choice for sustainability drivers. The leaves from the plant are fermented in a steeping vat, and then a liquid is extracted and oxidized from these leaves. A blue solid forms at the bottom of the vat which is collected and dried to form the powered form of the dye, which is later used in textiles widely.
Indigo has mysterious colour fastness properties since ages. The chemical properties of indigo dye remained baffling well into the 19th century. It was so challenging that fables arose around the dyeing process. In Bhutan, pregnant women were not allowed to go near the vat, fearing that the unborn baby might steal the blues. Women in Morocco believed that indigo’s fastness was too much to be true and the only way to deal with the challenging vat was to start telling outrageous lies about its usage.
Once dyed, indigo is so colourfast that it can last for centuries. It is different from all other natural dyes as it needs no mordant or fixer to set the colour on the fabric. It is insoluble and sets down on the fibres as microscopic particles without any need to form a chemical bond with them.
Indigo also has a spiritual relevance as a colour. Alice A. Bailey used indigo as the “second ray” representing Love and Wisdom in her classification of people into seven metaphysical psychological types, one being indigo.
The tone of indigo used in spiritualist applications is “electric indigo”. This colour is also used in New Age philosophy to symbolically represent the sixth chakra called Ajna which is said to include the third eye.
This indigo-coloured chakra is believed to be related to intuition and spiritual knowledge.
Indigo children, according to a new age concept, is a category of people who are believed to possess special, unusual, and sometimes supernatural traits or abilities. The idea is based on concepts developed in the 1970s by Nancy Ann, a teacher and a counsellor, who studied the electromagnetic field surrounding every living thing.
She noticed that 80 per cent of the children born after 1980 had a new deep blue coloured auric field. Though there existence is not scientifically proven, but the new age researchers believe that indigo child is here to bring us closer to our true essence.
Though it’s easy to find this colour on textiles all around, this specific colour is also rarely spotted in the nature. A fungi species of mushrooms called the Lactarius indigo is one of the very unique species of mushrooms coloured in tones of blue. Even more, birds are also found donning this colour on their wings sometimes. Male indigo birds too are of very dark metallic blue colour. The Indigo Bunting, native to North America, is mostly bright blue with an indigo head. While even more elated blue is the grosbeak species. This tone is also found in the reptiles as the eastern indigo snake, Drymarchon couperi, is of dark indigo blue colour.