I'm in my 50s and have been dying my hair since my teens. This is the first time this has happened to me.
I dyed my hair last week, using Olia Intense 10-50. I noticed after I got the pack that it said it contains no ammonia (I have used them before without issue, but knew the dye wouldn't smell too strongly.
I've been blonde for a while, as my hair is 70% grey and my beloved darker colours go ginger and don't last more than a week or so.
Apparently the dye goes purple when developing (makes sense as it's an ash colour), but it didn't on mine.
I wasn't happy with the colour as it was 'warmer' than I expected and my hair was very light before I started. So I just used toning drops and it was fine.
I didn't wash until today (about 4 days after dying) and to start with assumed the drains were bad, but the smell was as strong wherever I went and sniffing a strand of hair, confirmed it was definitely my hair.
I've shampooed it four times and conditioned it twice, then put on hair oil and thickening cream to improve the smell, but it's still there.
I cannot imagine what is causing this. It smells like a salon with perming solution in...a really, really strong sulphur smell, from the hair itself.
I don't know if the product was mislabelled and was really a colour remover, but it didn't smell at the time.