Indigo is the best dye in use. The color varietals are dizzying and the applications are endless. It is a blue that captures nuances in nature that are hard to come by in dyes. For this reason, Indigo has had a long history of use. Its most popular form today is in blue jeans, which themselves are nearly universally appreciated the world over. Pictured above is a black and indigo textile used as a Japanese room divider, or noren, produced by Ricketts Indigo.
Source
Ricketts Indigo.