I have naturally black hair which I have permanently dyed "red" for years, turns out a very dark shade of red/black and looks subtle. Accidentally bought a shade a slightly different shade of red and applied it mostly to roots, running the rest through the shafts. It must be a stronger formula - my hair is very pinky/red especially at the roots. It does not look subtle or natural.
Is there a way to make this darker/ more black?
I don't mind whether that is a dark shade of red(almost black) or dark brown.
What would happen if I dye my dyed red hair a semipermanent dark brown?