When mixing the colors you want..........you must make the formula with 2 colors. One that is a NEUTRAL or a '0'.....for example 7/0 N.........or 4-0 N..... as you see here
to be 1/2 the formula
and the other half being the "tonal quality" you want.
- Eyebrow brush to apply color
Here are some more examples of color formula's:
if you need a formula and don't see it, here, join our group. . . . put up a photo of your brows & hair color and I'm happy to give it to you!