Nipple question

No, seriously. Not to sound too ignorant, but this is my first pregnancy. I read the article on Glow about nipples getting darker and sort of popping out. My OB mentioned that I have flat nipples, which may be harder to breast-feed with, but that they will probably protrude before then. My question is, do they ever go back to the way they were in color or dimension? Or is it just a permanent change?