Yellowy blonde, advvice for my next salon trip?

Basically within the past 6 months I've gone from very dark brown to quite a bright, but yellowish and brassy blonde. Everytime I go to the hairdressers I ask for the yellowy/ brassiness to be toned down but I always just end up with a brighter version of it. The past two times all they've done is added a full head of more blonde foils over the top.. I suppose I'm just bad at asking for what I want! And also, it's the bottom layer of my hair that's the brassiest, yet they always miss off this part when they do the foils... so I need some help on what to specifically ask for when I go next week! Like exact colours and stuff (I have absolutely no clue). I really want to achieve a sort of champagne/baby blonde (shown in pictures).. well at least that's what I think it is haha. At best I'd like to have the brightest one but if that's not possible all at once then that's fine! I'm also considering investing in some purple/silver shampoo.. would this do me any good and which do you recommend? Lastly, I was thinking of having my eyebrows tinted.. judging by my pics, do you think it's a good idea? I also apologise for my horrendous photos.. I couldn't find anything that showed my colour properly! Also it's really really bad at the minute because there's been nothing done to it in 5 weeks! Thanks for any suggestions.

First of all you photo is fine, lol. Ask the hairstylist if they use hi lift colour, if the don't, then when they apply bleach to your hair, the reason the don't take it through the ends is that its probably very porous and with it already being bleached. So let then do your roots as normal and ask them to tone the yellow down with an ash toner, this will cancel out any warm tones in your hair. Yes I would also recommend you use a purple shampoo to keep the warm tones at bay. I use Schwartzkopf silver shampoo, available at Sally's, it is a purple shampoo and I use it on my clients, I love it, but I am sure other members will recommend other purple/violet shampoos.