Pamela,
I myself took Berocca before I had my first child.  I used to work
permanent night duty and it helped me to stay awake at night.  I
continued to take them during my pregnancy and when in hospital after
having my son.  I never noticed my milk being a different colour to
the norm.  However I did stop taking Berocca on about day 10 due to
my son having severe colic and it was one of the things I eliminated.
 Not only did I find it to be associated with colic but he also hated
sleeping in the day (I would take them in the morning).  He would be
awake 13 hours a day, this being a newborn I was shocked.  On
stopping the Berocca, he began sleeping in the day and the colic
settled down.  I did also stop caffeine, but that was only after I
had already ceased the Berocca and I had already got results with the
ceasing of only that.  I have now had a subsequent pregnancy and
child and never resumed the consumption of Berocca, or caffeine for
that matter, for fear of a wakeful, coliky baby!  Hope this will be
of help to your client.
Val in Busselton, Western Australia
RN RM IBCLC