Hair decolorization refers to the technical process of technical used to remove the natural or artificial colour from the root (up to 1.5cm) or the entire length of the hair. The term essentially includes all the techniques that seek to make hair colour lighter and to create a new colour base to achieve any desirable new colour.
When decolourization is performed on natural hair it is called decolouration and when performed on dyed hair it is called decoupage. This process must always be performed by a professional hairdresser to ensure correct application that does not endanger the health of your hair and perform the necessary initial testing that will give you the desirable result. Ask your hairdresser for advise in order to follow the appropriate procedure suitable for based the length and type of your hair, to achieve a great result that will truly express you.
It is advisable to avoid decolorizing multiple layers of hair at the same time because it is a very aggressive approach that can damage the hair irrevocably. Depending on your current hair colour, you may need to wash and dry hair before repeating the process as needed until you achieve the desired colour.