You could cover it with backpainted glass for a very contemporary look, and frame the fireplace in a dark color; it would be striking.

You can't white wash it - because the other colors would show through the wash. You can get paint for brick that should also adhere to the rock in the same way. If you are considering a gas insert - the places that sell them also do re-facing work. It's such a big flat area you've got there I'm sure the options are endless. I have a painted fire place wall in my home. I chose a color called Linen & you can't believe how beautiful and modern it looks. A mirror (or some kind of art that is heat resistant) above the fireplace and a new fireplace screen would also help really liven it up and give the room a sense of space.

This is what we've done with fireplaces similar to yours:
Venetian Plaster or new stone.
We've also applied lightweight concrete, but I don't have an image of that one.
:) Rhoda

Could you stain the stone with a concrete stain maybe ?! Or do you just hate it and want it gone !!??!

You can give it a yellowish or yellowish white paint. These colours usually make everything look good. But this my idea .