it looks similar to when i leave pravana chromasilk silver over my freshly bleached hair for too long, youd have to get your hair very pale, inside of a banana shade.
Use three boxes of a colour remover such as colour b4 extra strength or colour oops to get rid of the dyed brown hair to lighten it up without causing unnecessary damage, leave it a week or two shampooing a lot in between to ensure you dont get any re oxidisation when you eventually bleach.