Indigo is a dark blue color based on the traditional dye of the same name. The dye was discovered around 6,000 years ago and is traditionally used by multiple civilizations including Peru, Mesoamerica, China, Japan, Egypt, Iran, India, Africa and the indigenous peoples of North America. Indigo was well known to the ancient Romans and Greeks where it was imported from India as a luxury. Indigo dye can produce a variety of colors but is primarily a dark or light blue that is often slightly green or violet. In 1986, some programmers created a list of color names for a unix system known as X11. Having no background in color theory, they placed indigo as a dark purple. This list was later used by HTML and CSS standards that remain in place to this day. These standards are used by millions of designers and digital artists such that the color name indigo is now strongly associated with dark purple or violet. As such, a few programmers accidentally repurposed a color name that was known to civilizations for thousands of years. The following are common types of indigo color
Japanese Indigo #2
Tropical indigoAbove: note the difference between Web Indigo and Indigo. This standard color name is completely detached from the traditional color. This misrepresentation resulted from the random selection by a programmer working on an operating system in 1986.
AssociationsIndigo was historically a common and important dye such that it is associated with vintage clothing in many cultures. For example, indigo kimono in Japan have an Edo-era feel to them. Indigo is immersed in history, tradition, culture and folklore such that it has a different meaning in each culture.As a natural dye, indigo has an organic and earthy feel. For this reason, it was popular amongst the hippie subculture of the 1960s. This is perhaps its strongest current association.
NotesSome indigo dyes look purple when faded by sunlight e.g. the color of Tropical Indigo above.Indigo is a natural dye but synthetic versions also exist.Blue jeans are often dyed with indigo giving them their characteristic blue color.