here is one idea for the cesuo floor tiles: quite large dark grey tiles (not marbled, but plain grey). Maybe something like these would be easy to find?
Or a large tile pattern, like one of these (2 types below).
here are some images and information for the chufan and cesuo materials and design.
Chufan grey with with subway brick tiles.
Here are some images from the 1000 per metre suppliers (two companies listed below).
The company is
The next company is
Here are the tiles we thought might be good for the chufan walls:
Here is a cesuo basin a little like I think Cat likes:
Here are the two choices for the floors tile for the chufan, woshi, and balcony.
Here are some images for the cesuo tiling and design. The first set of images has the white brick tiling.
We could tile the bricks up to just below the top of the window (as in the photo above where the tiles go to just below the upper line of the mirror frame).
Maorr, you thought maybe grey below and white above?
Some colour might be nice.
One way to do that would be to use green/blue/grey subway tiles from the floor to hip height, and then subway white above.
Another way would be to use the green on the mirror wall and then use white on the other walls.
A third way would be to use So the colour tiles to grey floor tiles to hip height on the wall and then the green above:
One idea for the cesuo floor is these mosaic tiles:
They maybe go well with grey or white subway tiles, or the big white/ink tiles Cat likes for the chufan walls or similar. A similar one is this below:
But I think you found some like this you like already Meili Maorr.