The hearth relates to the black TV screen and the firebox. If you ever upgrade to a Frame TV, that might be a good time to replace the black stone with a light colored stone.

I think the hearth would look fine w/the new tile.

If you did the mantle in a similar oak, and style like this, I think it would look good. (ignore the the tile on this one and imagine your green ceramic)

I like this zellige too (c further below for that) you see how it's finished above?

and they kept the inlaid black hearth

you could also do some vertical shiplap above the mantle, going up to the ceiling like shown above the bench here:

I like this design w/the mantle. you don't have to do the white one too. the wood is fine.

You could also opt for a marble hearth in a mosaic, or try and find a remnant piece of marble w/those blue/green colors

this basketweave w/the green dots would be pretty(look up white thassos and green marble)

If you did decide to change it, I'd think about doing a glass tile mosaic that works w/the tile surround. it would look more 'beachy'.

something like this beachy looking glass tile (for the hearth)

either that, or something like a cement pattern tile

I love the look of this fireplace/room. I'd copy the whole thing!

How about Zellige tile? I'd actually do something like these for the fireplace surround topped w/the white oak mantle.

here's the beachy blue/green shown w/the black hearth. took it all the way up

you could also do the 2x2 zellige tiles on the hearth. they come in beautiful colors

here's one w/the tile on the hearth, trimmed out w/the oak wood to match the floor.

similar color you like w/the terra cotta hearth. I don't know what kind of furnishings you're doing?

or, this would look cool on the hearth and around your fireplace.

its a 2x8 cement tile.

https://www.tilebar.com/sample-colorone-robin-egg-blue-2x8-matte-cement-tile.html

if you used it for the surround too, it would look like this in the herringbone:

here's the black zellige. you could take it all the way up to the ceiling

here is a similar idea in the 4x4 blue zellige. it's stunning.

Serene Design Vacabulary, Richmond · More Info

photoshop w/updated fan and a diff tile

or you could do something like this^, keep the hearth.

STyle the rest of the room in this manner:

lots of options

did you already purchase the tile?

https://www.wayfair.com/Moroccan-Mosaic--Zellige-2-x-6-Terra-Cotta-Brick-Look-Wall-and-Floor-Tile-MSC060-L2970-K~MMTH1794.html