Tips on getting this warm grey with lilac-ey hue?

Hi! I went to a salon last summer to get this hair done, but surprise, surprise, it didn't look anything like this. I've been recommended to use Nirvel Grey to get this warm type of grey, but alone the undertones in that dye are more plum and minky (it's still a great colour, love it). I've tried to mix in some diluted violet but it kind of interferes with the whole warm thing that's going on 😀 Maybe I should add pink? Maybe buy a colour that's already pastel in the tube, so it won't have as much pigment? I'm having a really hard time trying to imagine what to mix with what *puzz* I know it's probably a very hard colour to achieve and to keep up, but I want to try nevertheless. I've seen people get kinda this hue with just Clairol Shimmerlights shampoo, but that's not available for me 🙂 Though I could purchase it online if it turns out to be worth a shot. Also Crazy Colour Platinum seems like this in the swatch, but I don't know if it really is like that. Oh, and my hair is already a pale blonde base 😉

Thanks for reading!