Meso-1st- I think you are trying your best to be respectful, and in no way did I take you for a perve or anything.
Having said that--I feel the need to point out that your wording could easily come across as offensive. You describe them as "huge" and then give an approximate diameter. Think now, about a woman reading this who maybe has 3" or even 4" areolas, and you're expressing your shock (while understandable, given your limited exposure to real women
)and labeling them huge. That can be a real 'ouch' to women who may be sensitve about this.
When I say real women, I mean just that. Not airbrushed, specially selected, surgically modified women that you're likely to see in Playboy and p/ornos. Some women in that industry (and others who are very self conscious) actually have tattoos on their areola to even them out, give them a more desirable color and better definition. Implants usually actually make the areolas look smaller because they fill out the breast more, and well, photoshop can do wonders.
Think of it worded about penises "I was working at the LTC and when I went to insert a foley-this residents penis was tiny! I'd say about 5 inches in length. What effects penis size?" I'm sure there are plenty of men here with that sized penis. A statement like that could set off all types of insecurities...
I'm not trying to nit pick or put you down-just to point something out that may not have otherwise occured to you.
To answer your question though, pregnancies, hormones, genes, breast fullness, sun/tanning light exposure, sheer luck, and sometimes breast size can effect the size and color of the areola. I've seen mamas with let's say a 32A with most of the breast being areola. I've seen 48DD mamas with quarter sized ones. and with many women, yes, the hyperpigmentation stays, though usually to a lesser degree.
BTW-If you haven't "gone there" yet in your clinicals--this also goes for labia majora and minora. Also, don't be surprised if one is larger, fuller, droopier, etc than the other (and I'm talking breasts and