Newly highlighted hair

[Cantstopthewaves]

I have natural mousy hair and I've recently had some ash blonde highlights put through it. I've been using Head & Shoulders shampoo but I'm worried it will strip out the ashy toner.
I'm looking for a shampoo and conditioner that I can use every 2 days that will keep my highlights looking fresh but I don't want a violet shampoo as they dry my already quite dry hair.
Looking to spend under £5 each.
Help!

Garnier bannan ones are fab, gentle on the hair and not filled with nasties.

I had a permanent colour a couple of years ago that was far too dark and I hated it. Some of the advice I read suggested using Head and Shoulders as it fades the colour quicker as it is so harsh. I wasted my hair about 20 times that week (yes really, several times a day) and it definitely fade my colour significantly. So based on that I would suggest swapping to a gentler shampoo if possible

I think the violet shampoos are only meant to be used occasionally. I buy Avalon organics and use a hair mask or conditioner every few washes.

I've been absolutely loving Bleach London conditioners the pearlescent one over the silver one. Not drying at all. A little over £5 £6.25 in Boots.

And then OGX Argan oil for shampooing, rotated with a giant bottle Elvive Colour Protect --cheap and effective.