No, there are two limits:1/ on natural hair, you can lighten a maximum of four shades (for example, go from a chestnut to a light blond); 2/ if the hair is already colored, you can redo the same shade or darken the hair, but it is impossible to lighten it without using bleach.
The oxidation colon process does not get rid of the pigments (natural or artificial) present in the fiber. It just oxidizes the pigments present and changes them for good. On natural hair, it works really well:you can lighten (up to four tones), darken, add highlights... But on colored hair, it's more complicated. “The chemical molecules involved in the oxidation reaction do not have the power to oxidize artificial pigments, explains Frédéric Mennetrier, they are superimposed on the previous colo. If you want to go dark, it works, because the dark pigment always takes over. On the other hand, if you want to lighten, at best nothing will happen, at worst it can create a third color that is not necessarily pretty (ugly reflections, a color that varies in places, etc.).
Thanks to Frédéric Mennetrier, colorist at Atelier Blanc and L’Oréal Professionnel expert, to Rodolphe Lombard, colorist at the Couleur par Rodolphe salon and to David Merveille, Schwarzkopf consultant hairdresser.
