Just a note on the hands, from my limited experience dyeing resin ball jointed dolls, (and also once I dyed a knockoff 1:6 adrien brody head dark brown for giggles)
if you sand or cut the surface of the hands they will take dye more closely in colour to what you expect from the bottle. I’m not sure why as the chemical process should be the same, but with the head I dyed, the areas where I cut off the hair to make a bald head (don’t ask) took the dye beautifully, where the face went a sort of greyish brown and then as I poured more dye in eventually went greyish black and I ruined the whole thing. I had cleaned the paint from the face with a solvent so it wasn’t residual varnish or sealer or whatever they put on these things, just something about sanding made it pick up the dye better. Just that hands and faces are very fine so there’s not much you can sand off them! could be useful info to you anyway.
if you sand or cut the surface of the hands they will take dye more closely in colour to what you expect from the bottle. I’m not sure why as the chemical process should be the same, but with the head I dyed, the areas where I cut off the hair to make a bald head (don’t ask) took the dye beautifully, where the face went a sort of greyish brown and then as I poured more dye in eventually went greyish black and I ruined the whole thing. I had cleaned the paint from the face with a solvent so it wasn’t residual varnish or sealer or whatever they put on these things, just something about sanding made it pick up the dye better. Just that hands and faces are very fine so there’s not much you can sand off them! could be useful info to you anyway.