Have you thought to stain it?

The problem is no matter what you do you have a larger problem by having the TV placed there. Otherwis you could hang a beautiful vertical print and be done. not sure how you would apply a mantel over the brick work in this case.

If you painted the walls a warmer color rather than the complementary green, the red in the brick wouldn't pop so much. I think it's a handsome fireplace, BTW.

following

There's always whitewash:

Liking white over it, but the red disguises the tv better... !

Move the TV to another location so you can hang a nice piece of vertical artwork. Then get rid of the green paint, which is highlighting the red. You could whitewash but it might just read pink then. A German schmear might be better.

Why no paint?

No additions like a mantel or wood surround. That will only call more attention and I don't think the fireplace style lends itself to any wood features.