Help! Yellow roots, high lift, toning?

[chicgeek92]

Hi,
I'm a blonde with a base shade 9n with highlights
Yesterday I did a root touch up at home using the wella 12/1 with a 30vol
I left it in too long, 45minutes and now my roots are quite lighter than I anticipated, with a yellow tone.
They do however match some brassy bits in between my highlights (rest of my hair)
I purchased the wella toners in T18 and T10 and want to know if it would be a good idea to tone it all, I'm afraid that it will lift and lighten my hair even more!
Anyone have any information to help me?
Thanks

 

[Elaine Armani]

Are you a hairdresser?
It doesn't say so on your profile.
If not you won't get any advice on here I'm afraid x