More about braces please!?

I'm getting braces in a little. I already know the process of how they put them on and things like that. My friend has braces and she had this wax thing to put on them when she first got them so they wouldn't 'cut' the inside of her cheeks. Do spacers hurt? And a couple days after do they still hurt? The last thing is what are some really cute color combo's to put on the top and bottom? That's it! Thx in advance!