What happens if you use a box dye lighter than your natural colour

[pastabest]

I appear to have been sent the wrong shade of hair dye with my supermarket shop. Instead of dark chocolate brown I've been sent light mouse brown.

I only use it to cover greys, if I use the mouse brown will the greys just go mouse (marginally better than grey) and everything else remain the same or will it turn my dark chocolate brown hair a different colour.

The colour chart on the box seems to suggest it will all go mouse but I can't see how that is possible without bleach?

I've done this before now. My hair is dark brown. It will dye the grey hairs the lighter colour and make no difference to the darker hair. The thing is though I usually find that even a light brown can be quite dark for the first week or so. So if you wanted to use it today, it would probably look alright for Christmas.

Most boxes of hair dye have a few pictures showing what the result will be with different hair colours. I've got mid-brown - now mostly grey - hair and dye it a lighter colour all the time, with good results. Is it a permanent colour? If so it will likely contain bleach or ammonia, and so will lift the darker colour out of your hair.

Well it's on now so we shall see in approximately 20 mins

When it's done, please let us know how it looks.

With box dye as they often come out darker it could be fine- or theres a possibilty you will get 'root glow' which is where your roots look lighter than your dark ends- as the darker colour on the ends will not be changed by the lighter colour, as colour doesnt lift colour. But that is easily rectified by putting a darker brown on the roots again.

I always buy a shade lighter than I want - box dyes run notoriously dark.

It might be just what you want!

I tried that once with a chestnut colour. It gave my brown hair a chest nutty sheen but turned my grey hairs pink.

It won't lighten hair that has previously been dyed with a darker shade. I wanted to change to a lighter colour and had to strip all the dye off first.

I've never heard of root glow before Mojitomogul but thank you for that excellent description of what has happened to my hair.

to add insult to injury it hasn't even coloured the greys

Thankfully due my haphazard approach to hair dye application now and in the past its reasonably well blended rather than being a solid line so I can probably get away with it.

Good job there isn't anything important happening over the next week

Thanks for the update.

I use a lighter colour than my shade of (red) hair so that the white hairs blend in.

Works well.