Schwarzkopf Igora Zero Amm 7-21 Medium Cendré Ash Blond 60ml - permanent hair color

Permanent colouring.
The system is based on a combination of up to 4 numbers.
The number before the hyphen indicates the tone height on which to use the shade.
The first number after the hyphen indicates the primary highlight - the second number after the hyphen indicates the secondary highlight - two identical numbers after the hyphen indicate the reinforced main highlight - the third number after the hyphen indicates a minor highlight.

Mixing ratio 1:1 for normal colours.
Mixing ratio 1:2 for super-lightening special colours.
Application for natural hair: apply first to the mid-lengths and ends.
After 10-15 minutes apply to the roots.
For regrowth: apply first to the roots.
After 15-30 minutes use the Dual-System technique on the mid-lengths and ends.
Application time: less than or equal to 30 minutes 10 volumes (3%)
30-45 minutes 20 volumes (6%)
30-45 minutes 30-volume (9%)
30-45 minutes 40-volume (12%)