These two categories are two which CAN’T be mixed with the regular hair color system. Meaning, you can’t color over these, they either have to grow out or be removed.
Metallic Hair Dyes are most popular for men. They use metallic salts which will color and coat the hair, gradually adding more color with each use.
Henna coats the hair and colors. It will create a coating around the hair each time it is used making the hair shaft impenetrable for other colors. Mostly, henna will thicken the diameter of the hair texture as it colors.
Henna does contain metallic salts and metallic salts react with chemical hair coloring. It will produce heat, heat that will burn!
This is why it is important to remove before using any chemical form of coloring.
