sas - what is your circulation like to hands & feet generally? The only reason I ask is that nipples turning white, blue or purple can indicate a condition called nipple vasospasm - I get it too. I also have really poor circulation to my extremities and have been diagnosed with Raynauds disease. Its not serious, it just means I get really cold hands & feet.

I have fair skin and pumps seem to be really harsh for me and my nipples are prone to damage, so I have to take it nice & gentle. Maybe like Fleur suggests, adjust the settings and see if that makes a difference. Like attaching a baby, using a pump shouldn't be painful or cause discomfort in any way. If you know a qualified LC maybe see if they know something about vasospasm?