Hi, I'm not sure if it can look like a rash but the first colour your nipples will go is very bright red, then purple, then white as it gets more extreme.
Does the pain go away by the end of the feed or is it painful all the time? I found that it was agonising when dd first latched on but about 5 minutes in it wasn't painful any more as the circulation had been sucked back in iyswim.
It could be though that if the pain isn't going away but is getting worse during a feed that maybe you are getting vaso spasm not from a severe reaction to the cold but due to compression of the nipple during feeding - what shape are your nipples after the feed?
I know it can feel itchy at first which is why it is often mis diagnosed as thrush - also it can be caused by some trauma to the nipple so thrush can bring it on and then you ended up being treated longer term for thrush when actually it has gone and you are having the vaso spasm symptoms.
Is there another bfing counsellor that you can see? I think this is actually a fairly common thing so it would seem a bit strange that she doesn't know anything about it but maybe I just got lucky with the bfing counsellor I saw.
This might be helpful to you from Kellymom
www.kellymom.com/bf/concerns/mom/nipple-blanching.html
Not really sure what else to suggest, whereabouts are you? If you want to e-mail me my address is below, I can put you in touch with the bfing counsellor I saw and she may be able to help you, or at least send you some better information. I can't access my personal e-mail from work (am skiving!) so it would be this evening before I can get back to you with that.
In the meantime try and keep warm, if you can get one of those wheat or rice bags you stick in the microwave to put onto your breast after the feed and if you feel it starting try and get warmed up as quickly as possible.
Get your dp/dh to read this stuff as well, my dp suggested we get formula a few times as he needed to do something when he saw me in so much pain but I really didn't need to hear that at the time and just wanted sympathy!
Wow that was long - hth though.