I have tried everything to get rid of this around the shower /bath
particularly on the silicone round the bath .I have tried bleach which
did nothing ,Screwfix's No-Nonsense mould spray which again did
nothing .I got the other day Lakelands Mould Remover which you leave
on for 2 periods of 30 minutes .What it has done has taken away the
blackness and lightened it to a sort of pale putty colour which
doesn't look so obvious .
I guess the only real answer is to strip out the silicone and renew it
and scrape out the grout where it is affected and regrout and wipe the
surfaces down each time it is used .