I'd heard the word before; I knew it was a color. I knew it was dark; it was often used in reference to night, or ink.
It was the first watercolor pigment I fell in love with. It was so bold, so strong on the little swatch card I was making. At the time, I was still struggling to get rich colors from my little dried out pans of watercolor, and the intensity of the color immediately grabbed me.
I started collecting the color in all the brands I came across. I have it in Winsor & Newton, Daniel Smith, QoR, Shinhan, Holbein. Each one is a bit different. Some explode across the page, some lean more towards blue and other towards black. The pigment mixtures are all different as well. I find myself going back to it again and again for my darkest dark. Maybe I'm biased (ok, obviously I'm biased) but it looks good with everything. For me, Indigo is the "little black dress" of my rather large collection of watercolor paints.