Yep my friend (and her daughter) were utterly gobsmacked at how hard black was to get out. It was flagged up as a 'temporary dye' that washes out in approx 16 washes. So maybe 5-6 weeks with an average of 2 to 3 hair washes a week.
However, although around 20% of the dye washed out within about 3 to 5 washes; the other 80% wouldn't budge at ALL. It made the girl look like a badger yes, and her hair was all patchy. It looked awful. She washed and dried her hair around 15 times over 3 days, and the remaining 80% stayed put. Upshot is, it was pretty permanent.
And as has been said, black dye looks SHIT when it's coming out. It literally only looked OK on my friend's daughter for a week or two, then it started to look messy and patchy. As a pp said, blonde/light roots on (dyed) black hair looks awful. Almost farcical actually, and yeah, people at school laughed at her, and mocked her...
Never ever, ever go for black. As with my friend's daughter, (and girls that other posters know,) it could cost potentially £150 to £200 to put right.
@Springwalk I think tattoos and piercings are much worse than dying your hair, as that is rectified fairly easily (usually,) and isn't 100% permanent, whereas tattoos and piercings are... However, you do make some valid points.
I did a quick google search, and it seems hair dyes and bleaches are not recommended for under 16s. There are warnings on loads of websites!
www.bbc.co.uk/news/uk-wales-41796586
My friend's daughter was about 3 months from being 16 (So it wasn't THAT far under 16.) But 13. It has to be a 'no' surely???
But yeah, you do have a point!!!