I have tried everything over the years. Absolutely everything. Blue shampoo, purple shampoo, expensive toners, you name it. Every single time I have my hair dyed brunette (I'm naturally brunette), whether I dye it myself or go to various super-expensive hairdressers, my hair hair fades to brassy orange awfulness within a few weeks, especially in the summer and I HATE it. The only thing that remotely worked was Aveda Black Malva conditioner but now that's been discontinued.
Anyway. Turns out I needed, not blue, not purple toner, but GREEN. I've found Matrix Dark Envy and it actually bloody works!! It totally counteracts the red orange from dark hair and leaves it properly ASH brown. It's about a tenner from Amazon. You need the hair mask, leave it on for ten minutes (use gloves, it's messy), rinse off and your hair is dark brown again and in lovely condition.
I don't work for them, but I do want lots of people to buy it so they don't discontinue it 
I often see posts on here asking how to get rid of orange/brass from brunette hair so thought I'd share 