Have you visited your local independent tile stores (not big box)? They are filled with many variations of marble-look porcelain tiles like the ones in your inspiration photo.

^ agree, bring a sample of your floor tile and counter along with a cab door and they will totally help you find something

I did, looked a Florida Tile, Arizona Tile, MSI, Dal Tile, Statement Tile, American Olean, Z Collection, probably 4-5 more I can't remember. Most are very busy and overwhelming. I thought this tile from Florida Tile (Precious) was perfect on a sample, until I looked it up online. Very spastic.

It does look better in small format, somehow looks less busy.

Where I live there’s a smaller local tile shop where all the tile pros get their materials - do you have anything like that?

i like the smaller format you show above - i tend to like very simple tile bc I don’t get tired of it

@la_la Girl yes, I've been at our local tile shop, they carry all the quality brands, largest selection around. I agree that more simple is better, would white subway tile be too simple?

Usually good design dictates only one "drama queen" allowed in a room: backsplash, countertop, flooring, cabinet finish, etc. You appear to have at least 2: large format floor tile in a dark gray, and wood patterned cabinet fronts. With the selection of a busier backsplash, you might end up with 3. I suspect the design suggestion has to do with giving the eyes a place to rest after the high contrast of the "drama queen" element, though I can't say for sure. I suppose if you want the "drama" to be the cabinets, you can cover up the floor tile with large format rugs. I personally like the flooring, especially with your beautiful tub. I'd paint the cabinets personally and let the tub be the star of the bathroom. You must've paid a pretty penny for that element. It'd be a shame to not let it be the "main event".

With that in mind, I agree with one of the other posters: a simple white subway tile with little to no pattern, again, to allow the eye to continue to move to the tub. You can use pretty colored towels and throw rugs as the "Jewelry" in the room.

These forums are very pattern averse. There is no design rule about only one "drama queen", although it seems to be a religion on these forums. LOL

You can have very good design that mixes patterns and/or colors, but it is a bit harder to do.

I would not consider a basic dark gray tile as being anywhere close to a "drama queen"!

OP you need to find your local tile stores that carry the mid/high end products from smaller ceramic tile manufacturers in Italy/Spain/Portugal.

These tile companies carry several muted marble looks. See if anyone carries their products near you.

https://www.atlasconcordeusa.com/porcelain-tile-collections/?89=505

https://www.florim.com/en/products/effects/marble-effect-tiles/f/marble

Here's a slightly different direction:

https://www.specialtytile.com/tiles/bazalt/

https://www.specialtytile.com/tiles/delicate/

Can you continue your floor tile into the shower?

Our shower looks just like your original inspo and we love it except our theshhold is white and adds a nice touch between the gray floors. We used real honed marble and it has etched but you can't beat the look IMO. Found a marble remnant for the countertop.

It is important to find an installer that understands how to lay out the pattern so the grain flows nicely and is not chaotic looking.

Also important in man-made tile that repeat patterns are not side by side which can be very obvious and lessens the natural look.

It helps if you would be there help lay them out on the floor when they are unboxed to ensure they look like you want once they go up on the wall. Make sure they are all from the same dye-lot...common problems here on Houzz.

Maybe this https://www.cletile.com/products/bianco-dolomito-white-stone-oversized-subway-6x12?sku=DM10004