Patch test for purple shampoo?

[PurpleyBlue]

Hi, I bought some purple shampoo and it says to do a patch test. Does that mean it has hair dye in it? I'm a bit nervous to use it in case it dyes my hair purple! Do they all advise a patch test?

Having spilt some on a carpet I can confirm that the one I use at least definitely contains dye . No purple hair though!

Just don't leave it on too long! What one did you get?

Kerastase Bain Ultra-violet as I like one of their other range. I got cool blonde highlights put in so I'm hoping it keeps them fresh.

@TheFallenMadonna

Having spilt some on a carpet I can confirm that the one I use at least definitely contains dye . No purple hair though!

Thank you! I'll do the patch test to be safe. It looks kind of like fountain pen ink what I can see of it without tipping it out!

Ah I have t used that one. Depends how light your hair is, if it's platinum you might find the shampoo leaves more of a purple shift behind. If it's more of a golden, wheaty colour you can leave it for longer.

It says minimum 2 minutes so I'll start with 1!

I'm guessing if it does go purple it will washout eventually?

Not used Kerastase but have used loads of others - Schwazkopf silver is my favourite.

Your hair is unlikely to go purple purple but might take on a bit of a hint if you get too much product build up.

If that happens just stop using it for a bit.

Do any of the other purple shampoos say to do a patch test. I'm just thinking if I'm meant to do this 48 hours before I use it every time then I'll just have a constant purple patch behind my ear as I was planning on using it twice a week!

It would only mean patch test once and this is purely to cover their own arses in case you react to it.
It won't dye your hair purple but if your hair is porous or you leave it on too long it can grab and you will have some purple in your hair but it washes out quickly.
I have a random bit of hair that always grabs purple but it doesn't on the rest of it.

It says to do an allergy test without fail 48 hours before every use! (All in bold) Which has surprised me. Just wondering if maybe some of the others are less chemically and might be better for next time.

I've just checked my bottle of Touch of Silver and it doesn't say that - which is a relief as I do have allergies to hair dye which is why I'm bloody grey in the first place!