Q&A for How to Color Grey Hair

A demi-permanent color uses dye molecules that penetrate the outer layer of the hair shaft but unlike a permanent color, it doesn't break down your natural hair color. This results in a color that is fairly long lasting but gentle on the hair.

You can dye hair that has gone a day or two without being shampooed. However, if it is very dirty it may impact the hair's ability to absorb the color.

Demi-permanent color usually lasts 6-8 weeks. If you shampoo frequently or if your hair is damaged, it may fade more quickly.

You can achieve fairly strong coverage with henna. If you want a darker color, use henna first, then apply indigo as a second process.

Your stylist could be using a 1:1 or 1:2 mixing ratio and is likely using a custom-made formula. Your best bet would be to ask your stylist because no one else would be able to correctly tell you your stylist's "secret" other than them.

You should begin with a 20 volume developer. It's a safe volume to use for at-home coloring.