Yellow shining through toner

Hi community, so I bleached my hair and got it to around a shade of 8/9. After this I decided to use t18 and a 050 additive. I mixed them using 3/4 of the t18 and 1/4 of the 050. I left it in for about 25-30 minutes and it turned silver but the yellowish tint is still coming through. I was wondering what I should do to make it darker and not have the yellowish tint come through?