Hair Colored Girl

Products that avoid the side effects of most industrial tints are available. The safer alternatives generally contain fewer potentially toxic compounds or are plant based. Temporary, semi-permanent and permanent exist with the same persistence as the industrial versions. In practice the results produced by these products often do not last as long as industrial tints. Allergic reactions are possible even from "natural" vegetable dyes.
Henna is a plant (Lawsonia inermis) used for Ayurvedic hair coloring. The orange dye is commonly used as a deposit-only hair color whose active component, lawsone, binds to keratin. It is therefore considered semi-permanent to permanent, depending on a person's hair type. Most people will achieve a permanent color from henna, especially after the second dye. With repeated use the orange color builds up into red and then auburn. While "natural" henna is generally a red color, variations exist. These variations usually contain ingredients from other plants and even synthetic dyes.
Indigo is natural dye from a plant(Indigofera tinctoria, suffructicosa or arrecta) that can be added to henna or layered on top of it to create brown to black colors in the hair. On the color wheel, henna is orange, and indigo is blue, so the two colors work together to create brown tones. Like henna, indigo may fade after one application, but it becomes permanent on the hair with repeated use.
Using a plant-based color such as henna can cause problems later when trying to do a perm or permanent hair color. Pure imported body art quality henna is claimed not to cause such problems, but most store-bought henna is mixed with additives which can lead to unpredictable results if the hair is later colored. Although it may not be visible on darker hair, the staining from henna will remain for several months and this may only be realized when dyeing is attempted and an unpleasant, permanent orange color results.