UK - Brand recs of black dye for stubborn grays?

Hi 🖤 😊 I used to use Polycolor Tint 'Natural Black' but it's no longer stocked in the usual stores locally; Savers/Home bargains.

I'm contemplating giving Garnier Nutrisse a go but put off as many colours I've had of theirs in the past (browns and blondes) have not been true to the shade. Can anyone vouch for their black?

The few I've tried so far and results;

Shwarzkopf ⭐⭐⭐Live Colour XXL 'Deep Black' - Comes out with too much blue tone for my liking but does stick well.

- Unsure whether to just continue with Live Colour and leave it in for less time? Or add in some warmth (I have some pink semi perms).

Nice n Easy 🙅‍♀️ - Really nice colour but barely last two weeks, same result with all of their dyes I've tried on my hair unfortunately.

TIA 💖