Thanjai Natural Indigo Powder is a natural dye that is very useful nowadays for coloring hair black naturally. It is common people known as black henna but it gives a blue dye. When used with natural henna powder it gives a dark brown to shiny black color. Generally it gives a blue dye even though it looks just like henna. It is also used to dye clothes and get a denim blue color. The Indigo powder is made using the leaves of the indigo plant.