Hair colour help

[BillieTheFish]

I'm having my hair coloured on Tuesday and I am just fed up with how it is. My natural colour is a sort of cool mid-brown. Not dark brown but not light either, definitely not brunette. But I've had it coloured for so long I haven't seen my natural colour in years. I've had balayage for ages and I am bored with it but I don't want to look wintry, the weather is like that already! But I don't want the yellow tinge that has happened to my hair.

Any thoughts as I am stuck.

Get the balayage redone and keep toning it at home to get rid of the brassy yellow with a purple shampoo or actual toner?

Like this?

@SlowlyLurking I do like that colour. I'd never thought of the purple shampoo. I thought it was for silver or grey hair.

Purple shampoo will take the brassy yellow out of any blonde tones. I have a similar colour to the photo, a little brighter, and any time it goes very yellow warm the shampoo will bring it back to 'normal'