Metallic Salts in Hair Dye: Compatibility & Hair Treatment

Question
Hi I heard a very long time ago that Nice & Easy contained Mineral salts and after using it I was Never to use any other color on that treated hair until the Nice & Easy was cut off. Is this true? why? Would cleatation treatment help? How is that done?  Thanks.   J P

Answer
JP,
 To my knowledge, this is correct. If you use a color containing metallic salts you cannot use an ammonia based oxidative color over it, as the color combining with the metal deposits on the hair would result in a chemical reaction that produces heat, and depending on the amount of metallic deposits on the hair, could conceivably melt or destroy the hair beyond repair.
 This is why you must wait. Sometimes the metals can be removed with something like Metalex, which is a color remover you can get at your beauty supply.
 An experienced colorist can also work to gently remove the buildup before re-coloring, but either way, you don't want to use a regular permanent color over it.
 Chelating treatments will not suffice. It is not enough to remove the metals.
Best of luck to you.
Stephe (hairman)