The pigment colour you see in the bottle on the therapist’s table is not the exact colour which will show in your skin. The simple reason for this is that the pigment will be placed under the top surface of your skin, so you will be seeing the resulting pigmentation through the colour of the skin. It’s like looking at something through sunglasses. The skin colour and skin undertone filter the actual pigment colour to produce a visible result which is the combination of all of them.
This effect is not apparent immediately because, when the pigment is first applied, it’s present from the surface down. There is still some of the pigment on the surface of the skin or in the epidermis, which is the top level of skin. But the epidermis is the level of your skin which is constantly shedding. That’s why the colour of the pigmentation will appear to change over the first few weeks. As your epidermis naturally sheds, so it is replaced with new epidermis layers which do not contain the pigment. The pigment is now only in the dermis itself. The new skin is then creating the sunglass effect I described. That is why you should never judge the eyebrows immediately after treatment. You have to wait for a few weeks to see if you like the result then.
To arrive at the right pigment colour, the technician needs to take into account your skin type and undertone. For example, if you have very pale skin and you are a Fitzpatrick skin type I or II, then your undertone is probably cool, and the technician will need to add some warm-coloured modifier to the chosen pigment colour to ensure that it counteracts the cooling effect of your skin tone.
A ‘modifier’, as the name suggests, is a pigment colour which can be added to the chosen pigment to modify its colour and thereby counteract the effect of your skin tones on the main pigment. Pigment manufacturers also produce lightening pigments which can be used to try to lighten an eyebrow colour which turns out to be darker than you want.
It is generally a good idea anyway to start off by going for the lightest pigment colour you think you would like your eyebrows to ultimately be. If it turns out to be too light, you can at least darken it at a second treatment. But if you start off at the very darkest end of your spectrum, it’s very difficult to lighten it again, if you discover it’s too dark for you.