I naturally have white hair. I have colored and dyed it for the 20 years . I have bleached it bring out the white hair but, it is about 20% yellow. How can I get it to become white? Should I now frost it?

Thanks

As you seem to have learned by your next post, you need to tone it, and the violet toners are the best.

"Frosting" or highlighting will not work. It will only damage your hair to the breaking point.

You apparently tried to bleach out the artificial pigment. It's frequently the case that these pigments only bleach to yellow. You can beat on them until the hair breaks and they won't get any lighter. You can, however, tone them if the hair is light enough. You can also use a darker (blonde) hair dye. The very best toners (absolutely the least damaging) for bleached hair are acidic demi-permanents

Let me google that for you