The dye itself was Clairol’s Soy 4Plex 8A/28D Light Cool Blonde — something available at salon suppliers. I also used a 40 vol. developer. As forewarning, I already had my hair bleached to hell twice over, so the damage probably helped it grab the grey/ash undertones more strongly than the dye’s intended outcome.
It’s pretty funny, I always thought it would be fun to have grey hair and have attempted it before. Turns out mistakes work best!