Using Manic Panic Virgin Snow on darker hair?

I have dark blond/lightest brown honey-golden whatnot hair. I did this by applying permanent gray dye (Wella Light Drabber with 40vol developer) to my natural medium brown hair. If I used Virgin Snow on my dark blond hair (which has plenty of yellow tones), would my hair go gray, brown, white, or just lighter? Or something totally different?