How to go black/blue?

it wont last long if you dont use bleach, or at the very least open up the cuticle with some peroxide.

I used to have a deep Blue Black hair colour for years but it was unfortunately a box dye from the chemists. It always worked well for me (I have naturally dark blonde hair) and I never felt my hair was in bad condition BUT I do know now that they're not great for your hair & if you ever want to remove the colour/go lighter it is an absolute PAIN of which I only know too well about 😮  :'(

You could maybe try out a few semi/direct black dyes that are more blue/purple based & add a bit of a dark blue to it? That's what I would try first. Not sure how well it will stick to virgin hair...it's something I have always wondered for when I ever go back to having black hair, so hopefully someone on here with experience of using them on virgin/unbleached hair can answer that  *anyone*