Please talk me through permanent hair dye

[M0reGinPlease]

I've got quite a lot of grey in my hair, but the rest of it is glossy and brunette. The grey is in individual strands rather than my entire head going grey, iyswim, so a block line of roots won't really be an issue when dying my hair.

I recently had a semi-permanent tint at the hairdressers which I loved but the cost is just prohibitive. I need to dye at home. I then used a semi-permanent at home box dye which I was fairly pleased with but the results didn't last long.

What are the main differences between semi and permanent colour? Will the colour fade as well as grow out? Do I need to closely match my natural colour (which I tried to anyway and got pretty close with the semi-perm).

I get my hair cut regularly and use good (salon) quality shampoo with a colour protector.

Any advice welcome!

Permanent dye goes right into the hair shaft whereas semi only coats it (I think). So permanent is more damaging. I've been using permanent dye for years though and my hair is fine. The box will tell you what the result is on different hair colours and which are not recommended. If you're just going for a similar colour to your own it should be fine. Permanent fades a bit (or on my case goes brassy!). Another problem to look out for is "root glow". If you do your hair at home you're unlikely to be able to just treat regrowth as easily so you do the whole head and end up with roots that are lighter that the repeatedly dyed length iyswim.