What happens if you use a lighter hair dye (no bleach) over a dark hair dye?

[Madeyoulook]

I went from blonde to dark a few months ago using a box dye. It’s fine but I’m now thinking long term I would prefer to go dark blonde all over. So it would be close to my natural colour but not too dark against my skin.

How can I achieve that without highlights and roots? what would happen if I put an all over colour on my hair that is lighter than my current colour? Is this something that is achievable in one go or gradually or not at all?!

Nothing.

It won’t do anything.

Absolutely nothing.

Oh I’m glad I asked now.

If you are very dark, I'd recommend getting this done professionally. They might even have to do it gradually over time. They'll have to use bleach to strip the colour out then use a toner to reduce brassiness/red. You can get colour removers to use at home which remove dark dyes but you'll probably be left with some weird patchy reddish/brown colour so would still need to get that adjusted. Its not an easy or straightforward job to go from dark to blonde and it will take a few steps to get there. It can be done, but I'd leave that to a good colorist rather than attempting it yourself.

Also- forgot to say, ask them to include Olaplex in the treatment- your hair will take a bashing doing this and olaplex repairs broken disulfide bonds in the hair which can happen during the bleaching process

Along the same lines....what might happen if one had very highlighted hair and wanted to use a semi-permanent dark blonde/very light brown on it,something like Casting, which says 24 washes ?
Seems a few of us are getting twitchy fingers this 'twist as

I had highlights for years and I don’t want to go back to bleach or stripping the hair or anything drastic. I thought maybe if I used a lighter dye it might tone my hair and I could gradually grow it out like maybe you would if you were growing out grey.

I disagree that nothing will happen.

I did exactly what you said with the lightest casting box over a really dark dye. It came out a sort of coppery dark blonde.

Not the most amazing colour but it did work.

This depends entirely on whether the original dark dye was permanent, semi etc. Plus if the box dye you put over the top had peroxide in it. Semi permanents wash out after 6 weeks so much easier to remove than permanents

Likely to turn khaki green. Needs to be primed with a red, or use a reddish tone color

Basically- semi permanents coat the hair shaft with colour so easier to remove and wash out eventually. Permanent dyes use bleach to force the natural pigment out of the hair shaft inside and fill it with another colour. Therefore putting a semi over a permanent won’t do much. But if you put a permanent over a semi you’ll get far stronger noticeable results because of the bleach content. But with blonde on top of dark the colour you’ll get is unpredictable because dark dyes have a lot of red tones in them so they’re likely to end up brassy looking which is why better left to professionals

Oh ok you’re putting me off now.

If you’re asking these questions you shouldn’t be anywhere near a box dye. Go to a professional, they’ll be able to achieve what you want without wrecking your hair.

It can be done! But as said, get a professional to do it then you’ll get better colour results and less hair damage if they include olaplex

Orange hair is a possibility

If your hair is dyed dark then a blonde dye on top will be essentially invisible. Like writing in blue biro on a black sheet of paper. To get it lighter you need to use bleach or colour remover, which are both harsh on the hair.

This is assuming the dark dye you used is permanent?

Yes the dark dye was a permanent.

You'll have to remove the dark colour before applying the dark blonde dye.

I tried this after being blonde for years & going dark in lockdown - ended up with a sort of gingery colour after using the at home colour remover but it was at least even & decided because I'm pale, with Scottish & Irish heritage and have a natural auburn tint to my hair anyway that I'd embrace it & go full on redhead.

My hair is now a light auburn/ginger & most people don't realise it's not my natural colour.

But in saying that I had a good experience with the at home colour remover - there are plenty of disaster stories out there.

Can I highlight my daughters dark brown hair with blonde highlights

Olaplex ruined my hair