Numbers on Hair Dye Boxes

Woman checking the numbers on hair dye boxes
Photo: Pavel L./Shutterstock
Q: I was wondering what the numbers on the hair dye boxes mean. I know it means the color and level and whatnot, but is there a chart or something explaining it all?
A: While there may be all kinds of numbers on any given hair color package, I am going to presume you are referring to the numbers 1 through 10 (or numeral/letter combinations with numerals 1 through 10) found on most all of them. These numbers refer are codes for the colors achieved through the use of the dye in question. Specifically, the numerals refer to the light-level of the color in question.
When gauging hair color, a scale of 1 to 10 is used to represent the lightness of the color of the hair. "1" is the darkest possible color level and would be a dark, dark brown or black, while a 10 represents the lightest possible color and would be a platinum or pale yellow blonde. The exact color achieved is determined by the lightness level and base colors in the hair dye.
Knowing this allows you to know that a level 3 with a red base color would probably be a rich warm color like auburn or chestnut brown. Conversely, a level 8 with a gold base color would likely get you a rich, vibrant blonde tone.
It's important to remember that the hair color result you get when using a dye depends on the color of your hair before applying the dye and the formula of dye to developer used to mix the hair color.
Most hair color has a cumulative effect unless the formulation allows for lightening of the starting color. If your hair is naturally a level 5 medium brown, and you add a level 5 color that is deposit-only (with no lifting action) the end result of your color will be darker than you expect.
There are sufficient factors involved in formulating and applying hair color expertly that seeking the services of a licensed professional are worthwhile. However, hopefully, this rudimentary information will help you understand a little better what color can and can't do for you.
See also:
How to dye hair
The 1 to 10 scale for hair color lightness
Color highlights with box hair color
Dye over a previous hair color with supermarket box dye