But what color is indigo? Turns out, that's a big question. A mix of blue and purple — and affectionately known in the Livingetc office as 'blurple' — indigo sits on the color spectrum ...

“It has no justification in experiment exactly; it just represents something that he’s imposing upon the color spectrum by analogy ... two colors—orange and indigo—corresponding to half steps in the ...

Here's how natural indigo is still grown and fermented in Japan, despite the fashion industry's dependence on synthetic dyes.