I think it will look good either way. Usually the niche tile is used in another place in the the bathroom as well but it shouldn’t matter much since it seems to match well and bottles cover it up in the end anyway. If you haven’t already… consider making the niche wide so it’ll fit more. Ours turned out a bit too small for all the stuff I’d like to put there. I like the middle and right floor tiles best.

Tell me more about competing undertones. Do you mean they aren't going to work? Is there a combination there that does?

In your photo, the 10x14 (not a popular size these days) and the middle 12x24 are both on the "pink" side. Your paint deck shows you want blue/grays; so in that case stay away from those mentioned above.

I agree with Skip.

We just did a master reno and at first tried to coordinate tiles. Got samples home and everything clashed. I am not a decorator, but knew they were off and didn't work.

We went with a tile that had everything matching.

We chose square mosaic for the shower floor, but it came in hex.

We used the same polished for niche. Highlighting a niche is a personal choice.

Polished on walls, unpolished on floor, unpolished square mosaic for shower floor.

Done! Easy.

Thanks for the tip, Chris. The niche has a shelf, so double the space!

Thanks, Eld6161! Your bathroom looks great.

Skip, I see what you mean. The wall tiles are from 2 different stores, both labeled white, but clearly not the same color.

can you put the hex tiles and the floor tiles in some natural light and take a pic?

do they work together? you never pick whites from two diff brands and expect them to match. they won't. Does the floor tile have a matching hex mosaic in the same style?

I like the middle large floor tile and the either of the hex. Is it a real marble or a porcelain? they look slightly taupe colored.

choose a standard 4x12 white subway tile for your tub surround. that's the same size I used in my shower.

your 4x10 size will look like this.

But I really like this one w/your tile choice. I hate 12x24 tiles! especially in a bathtub surround. unless you're after ultra modern.

this 5x5 Cloe tile is perfect.

a bit more contemporary. those are prob 3x12 tiles. the niche is a glass mosaic tile.

Or, why not pick a hex tile in the same shade/make as that floor tile? You have a lot of very white and muted tones and are doing a bold blue vanity.

did you know they make a blue marble look large tile?

You could do that on the floor, your white subway tile in tub surround (do the 4x12 size or even the cloe tile or something similar to it,) and bring in a blue penny or hex for your niche.

here's the blue hex w/a vertical stack offset in the subway tile

another option is a herringbone layout. you could do the back wall only, and a stcked layout on the other walls.