How to get rid of semi perm hair dye?

[Stillmonday]

I've been colouring my hair with semi permanent L'Oréal casting dyes for years now.
My hair is mid brown naturally but it's more black on the mid to ends as I've been using too dark a colour for way too long.

I'd like to go mid to dark brown again but how do I get get rid of the colour on my lengths without damaging my hair?

Anyone?

I used one of those "colour b4" things, which took a lot of the colour out. They are quite faffy though, and you have to rinse several times for about 10 minutes at a time.

I stopped using Casting and started using the Nice N Easy 8 wash ones instead, which don't build up in your hair like the semi-permanents.

As said above remove the colour with colour b4. Semi permanent don't wash out.
So either remove it and start again, cut it off or grow it out.

Does colour b4 damage your hair?

No it doesn't. It's very strange stuff which shrinks the molecules of the hair dye, making them small enough to wash out.

The first time I did it I didn't rinse it for long enough and didn't get rid of all the dye, so over about a week it gradually darkened again!

There are quite a few threads in here about colour b4 if you do a search.