Only oxidation formulas can completely cover white hair, because this requires opening the scales of the hair well in order to insert the pigment into a fiber devoid of melanin. If you opt for a less covering formula (at 70%, for example), white hair is reduced thanks to a veil of pigment deposited on the fibre. This is called "transparent camouflage". This is more than enough if you have little white hair. The bonus:there is no root effect!
The potentially allergenic element is a dye present in all oxidation formulas, paraphenylenediamine (or PPD), sometimes replaced by paratoluenediamine (or PTD). This is why it is recommended to test the product behind the earlobe 48 hours before the first pose. If you are allergic, do not panic! You can always highlight (bleaches do not contain PPD) or bleach and then recolor with direct formulas.
Because colorist is a difficult job, of course! This pro establishes a diagnosis of color (it can vary from roots to ends), material, condition of the hair, etc. He chooses the right shade, according to what is asked of him. And since he knows the rules of colorimetry, he can mix colors to make bespoke. Above all, it has a technique of application:it can subtly color a few locks, give relief by applying a lighter shade on the tips, obtain a hyper natural and luminous result...
Thanks to Frédéric Mennetrier, L'Oréal Professional color consultant and colorist at Atelier Blanc (6, rue Mayran, Paris 9th), and to Romain, creator of the Romain Colors XXVII salon (27, rue La Boétie, Paris 8th). ).
