If you're looking for a natural alternative to chemical hair dyes, you may want to consider henna hair color. Widely known as a dye which is used to create body art, this plant-based dye has long been used as a hair dye in India, Rome, and Spain for centuries and is gaining popularity worldwide.
The henna plant has a red-orange dye molecule that can be used to redden hair. Traditionally, henna hair color is used on darker hair hues and the color will survive several hair washes.
The results of henna can be very unpredictable, given that the concentration can be hard to control. Be careful working with henna for regular coloring tasks but think twice about using the plant to disguise grey hair. Henna will turn that lighter hair orange.
Since henna only has the power to dye your hair red-orange, some more adventurous dyers add ingredients to tweak the hue: cloves, coffee grounds, red wine or dried limes. You could also experiment with mixing another natural hair dye with henna. For example, walnut leaves or shells combined with henna make a brown dye while saffron or sienna when mixed with henna makes a blond hair dye.
Unlike a chemical dye, henna takes a long time to process. You may have to leave it on for about 4 to 6 hours to get your desired shade and even after you rinse it off, your hair color may continue to change or darken. If you are the type of person who doesn't like to be surprised or gets upset when hair color doesn't go their way, henna may not be the best option for you. Also keep in mind that, although it is a natural dye, it can cause allergies in some people, so it may not solve the problems so do a patch test and be careful before or while using it.