Coloring
Everything for coloring hair: dye, bleaching products, developer, color refreshers and conditioners. If you work at home, always perform an allergy test first and mix exactly according to the ratio on the packaging — that determines the final result. For drastic changes, from dark to blonde for example, you will get further with a hairdresser than with a box of dye.
What is listed here is professional material, and that works differently than a box from the supermarket. Dye is mixed with developer in a fixed ratio, and that ratio determines whether you lighten or only color. If the measurement is not correct, the color will not be correct.
Two things to do beforehand. An allergy test behind your ear, forty-eight hours before, even if you have colored your hair before. And a test strand on a lock of hair that is not noticeable, so you know how your hair reacts.
Bleaching is not coloring. It removes pigment and always damages the fiber a little, even when done well. Going from dark to blonde in one go is exactly the case for which you go to a hairdresser — that costs less than repairing a failed attempt.