Hi, not quite an answer, but a strong recommend. I don't know what colour your hair is, obviously. I used to be brown, with a warm, reddish-in-bits tint - but that was over 30 years ago, since when I have had ash-y blonde home colour kits, came out like highlights. Garnier is what I found the best, but I can't remember the number, sorry.
Some 14 months ago my hairdresser noticed that my roots had a lot of white and recommended that I grow my colour out (I'm 68) so I have done --- and I am VERY pleased with the results in that I now have silvery-white streaks, which would cost a fortune to recreate at a hairdresser's. She recommended (and I use) PRO-VOKE shampoo and conditioner (purple packaging) which brings out the silver and cools the brown. Hope this helps.