Well, take this as a lesson learned - stop involving her! After your wedding shower and wedding, I think you would have known! I don't mean to be snarky, but you kind of know what your mom is like.
That being said, yes, I would be upset that she'd do this. It's petty, immature, and mean and definitely not very "mom-like".
Now, if she actually said "wear pink in order to upset lauren", I'd hope that most of your friends and family would be like "WTF?" and would purposely NOT wear pink.
But if people do wear pink, laugh and move on. I'm not really sure what is "publiclyl humiliating" about a bunch of women wearing pink.
And again, never, ever involve your mom in things like this again.