Think long and hard about painting a fireplace if it is a working fireplace.
Think too about how long you are going to be in the house. If you are planing on moving anytime soon I'd think again about changing the fireplace. A good option if you aren't going to be in the house much longer so you can still get what you want is to use inexpensive plywood to cover over the brick and then paint.
Brick typically needs to be cleaned well and primed before painting. It's not easy painting brick as it will suck up lots of paint and applying it is not what I'd call a fun day of painting.

Thanks for the advice. I am actually on the fence about doing it. I've painted lots of rooms and trim before, but never brick. I didn't realize it would be much different or more difficult.

If you prime the brick, you should have no difficulty in painting it. I know Ben Moore and Modern Masters make nice metallic paints, but having never used them on a fireplace, I can't speak to how they would hold up near heat. But, I must say, it does sound really pretty for a contemporary setting!

As for plywood over the brick, if anybody is thinking of doing this, check with codes in your area. It sounds like a serious fire hazard to me.

I've never painted a brick fireplace, but painted our stone fireplace. It reminded me of a Medieval dungeon, the stones were very dark and depressing. I first primed the entire fireplace then painted each stone with a small brush, and finished the grout last. It was very time consuming but well worth the effort. It now looks like the colors of the Grand Canyon! I also went to Lowe's and spoke to the person in the paint dept before I started this project. Good luck!