Does the permanent coloring in the salon harm the eyebrows?
I believe that they will definitely not come out, but they can thin out in 10-15 years. It is no secret that any dye is a product of chemical transformations, and the dye over time makes the hair thin, weak. However, there are no identical people, so my statement may not affect you.
I have been dyeing my eyebrows for a long time, more than 10 years. And in the salon, and herself, at home with eyebrow and eyelash paint (I used different manufacturers). What the eyebrows were before, they have remained the same. I can't stop painting - I'm used to it :).
In theory, such coloring, of course, is not the most beneficial exercise for eyebrows.
In practice, I do not observe a catastrophe from long-term staining.
There will be nothing for the eyebrows, and if there is, you can safely tint them further! Women dye the same hair on their heads, even when they are already gray, or they have sparse hair. They are not afraid of the prospect of being completely hairless in the distant future, some very distant apparently. Do not worry! Now such a paint, it causes minimal harm to the skin, and even to the hair and even more so.
It depends on what means for eyebrows the salon abounds. There are more gentle paints, then they are no less harmful than from any other cosmetic product, but there is harsh chemistry, from which, indeed, eyebrow hair can thin out over time and lose its original natural pigment, chemistry will simply wash away his.