How can I change up this fireplace?

I love these types of fireplaces! ...your so lucky to have one! I see that the walls in the background are more neutral. You may want to change the bold colors on this fireplace too!

Painting the tile could give it an update!

I would encase all three sides with a stone veneer - it wouldn't stick out too far and it would make it a real focal point from every angle (so you'd have to take off the tile). Also I would paint the little bit of brass with high heat black matte. I think that would update it and you could one piece of art on each side to coordinate with your color scheme. Just my thoughts!

I think taking off the tile, and use a light wood to the same depth to enclose the fireplace would work. Then I would paint it a nutural colour, then add a picture each side to fill the space. If they are the same height all around it would look great.

Firstly, I would remove the tropical hummingbird wall art. It is competing for dominance with the hearth, resulting in neither being a winner.

As brass trim on fireplaces is dated, next I would suggest painting over the brass with heat resistant black paint.

Lastly, paint over the yellow wall with a paint color that matches the tile. This will integrate the surfaces on the wall, modernizing the corner.

https://www.google.com/search?q=three+sided+fireplace+ideas&tbm=isch&source=hp&sa=X&ved=2ahUKEwiQodmr0v3gAhVLWq0KHT8wBVMQsAR6BAgCEAE&biw=1093&bih=499&dpr=1.25