For what its worth, I think the blue, green and pink will look great together and you still have time to play with the shades if you start to feel like its going in the baby shower direction.
I think the dress and the veil are a good match. I'm not a historian so I haven't a clue if they appear to be from the same era - but as long as none of your guests are major history buffs, who will ever know anyway?! I think what matters is they are both very "you" and they both have the glamorous, dramatic look that I think you're going for. You love them and you'll feel great in them and be happy when you look back at your wedding photos later. I'd call that a win.
As far as the earrings I'd say go with whichever ones look best with the dress. (I could be wrong but) from what I remember of your mom buying you the earrings, it wasn't like she went out and carefully chose a pair and gave them to you as a surprise, but more like you two were at DB together, you saw them and liked them, and basically on a whim she paid for them for you at the register. Which is very sweet! But I TOTALLY don't think, if that's the case, that she will mind if you end up not wearing them. Also, she's your mom, she knows you, she knows you've made some changes and I'm sure she assumes there are more to come. Kudos to the person who can plan a wedding WITHOUT making changes! (I've been avoiding updating my own PJ for ages because of all the changes we've already made!)