How to achieve that blonde?

I wouldn't use a permanent dye, I doubt it will get your hair light enough to have that color + they usually have 40 vol in it which would just be overkill. I would bleach your hair to a golden yellow color, then I would use Nirvel Artx Nutre Color in Grey, heavily diluted over it. It is a very neutral, brown based, dark grey semi that tones blondes + gingery shades very, very well without leaving any blue or green tones to the hair at all. @BabyJ discovered it and @Alexia tried it out over her bleached blonde with some ginger and it looked gorgeous. I don't remember the ratio she used to dilute it, but I would dilute it a little more than she did probably to keep some of those neutral/warm tones like in the box dye photo you mentioned. I'm sure @Alexia would be happy to share her experiences with you too, she has a lot of experience with blonde tones

Yeah, I was worried about the double process. Nirvel Artx Nutre, I'll check if there's a way to get it here. 😀

That colour is a very golden blonde, you might not need to neutralise the yellow so much. There are ranges designed for blonde hair that add golden (rather than violet) tones. There are also various blonde toners such as Jerome Russells and the new Live XXL ones. If you can get to a sallys they stock coloured Mousses (Ion and Roux) and Wella Colour Fresh, which is a semi type of toner, which come in various blonde shades.

Yeah, that's the main problem: I live in Belgium. We don't have a Sally's. Back in the days, you had the real semi's like Guhl, without peroxide. Unfortunately, they aren't available anymore in local stores. The only thing I can get quickly, is Casting creme (L'oreal) but that does contain peroxide and no idea how much.

Another option might be Hennaplus, who do sell temporary dye (again without the peroxide) but just one single blonde.

Perhaps there are more brands quickly available online (and with not extreme shipping costs) but nobody is clear about the peroxide.

Have you looked for Wella colour Fresh? It is definitely a semi.

I'll check that one out as well. Is anyone familiar with Goldwell Colorance Soft Color? It seems like it's a semi but nobody is clear.

Whatever happened with stating ingredients? :')

I haven't used the Goldwell one, but it is a mousse, so i think similar to the Ion/Roux ones. I know you can get permanent dye in mousse form, but they come in a box and have a two part bottle to mix the peroxide in, a single can of product sounds like a true semi to me.

True, that's my problem with the Loreal Casting Creme thingy. The storeowner claimes it's a semi but I know for sure that's a demi.

Hmm. I still have some time before I try anything. At the moment I consider to use the Hennaplus as I can get that here downtown and I know that brand quite well (used their permanents for a while). I never thought getting blonde would be way harder than getting pink. At least without fried hair and/or hairdresser drama.

Edit: Oh, Wella is actually possible online. Options! What to buy?  😀

I am a level 6 and in the past they used a high lift lightest blonde on me and it did NOT get me to a pale light blonde. It was probably about a 7.5, MAYBE 8 in lightness, but very very reddish. That didn't last long. If I wanted a strawberry blonde color it actually was good for that, it wasn't a clowny color or anything, but I HATED it with a passion.

If you are anything darker than natural blonde, and I will venture to say level 8 blonde even though some say 7 can use high lift, you NEED bleach!!

I don't need a double process, my roots turn a slightly yellowish platinum like the inside of a banana, without toner.

Semi will not lighten you enough I am afraid.

I really recommend seeing a professional if you are turning your whole head blonde and then learning to do touch ups yourself.

My hair is already completely bleached, currently with faded cerise. My natural hair is way too dark for a blonde semi.

And due to past experiences with hairdressers, I don't even come near them when it comes too bleach. Or normal hairdye for that matter. Don't know what it is but several have really messed up my hair.