I'll be doing a very similar remodel in July and worry I'll be living in a cave. What color are you doing your ceiling? How many lights are you planning?

Here's mine, in progress, just to give you something to base on. It's slate on the floor. Since I don't have the window, I decided against the slate around the tub. I am also planning on white wainscoting, white toilet and pedestal sink. Without the widow, we needed a three light vanity light and a light in the vent fan just to make the room normally lit. I think I'm going to go with a shade of lighter grey on the walls. So far, we haven't picked the shower tile.

The ceiling will be white.
We have 4 lights above the sink and we are thinking about doing a recessed light in the shower.

When we used unglazed Italian porcelain tile in our shower walls, we used the 18 inch squares (or was it 16 inch)....but I opted for the same kind of tile, unglazed porcelain, in the 1/2 inch mosaic form mounted on 12 x 12 sheets for the floor of the shower. I figured that it would be no problem to slope toward the drain, nor would it cause any slippery footing issues.

The other day as I stepped out of the shower with no mat on the larger tile there, my foot slipped. I caught myself, so no harm done. But I know it was a good choice for the shower. I like the 1/2 inch size of the small mosaics. There are a lot of other choices you could make too, like the pebbles, or even glass mosaic. Lots of pretty baths pictured on this forum with different material on floors in the shower, than chosen for the rest of the bath.

Some photos showing the shower tiles. LARGE tiles are also on floor of this bath, and on the walls of the shower. The 1/2 inch mosaic unglazed porcelain sheets are only on the shower floor.

I did not use the flash here and the color is off.

And here is the marine grade light in the shower. It has a gasket to make it water tight for use in wet environments, but it is not what I'd call "waterproof." It is over the entry to the shower and does not show except when you stand inside the shower.

Doing every surface in the bathroom with a dark tile might make the small bath look a little ominous.

With dark tile you already know you need extra light.

I could envision the dark faux-slate in the shower on the floors and walls. As well as on the bathroom floor. On the bathroom walls, maybe on the lower portion of the wall as a wainscot, then transitioning to something lighter (more tile or just paint) on the upper part of the walls.

But it really is up to you and how your eye sees things. Judiscious use of a "dramatic" material makes it dramatic. Too much of a dramatic material can push it over the edge.

Here's an old thread where someone was asking about a dark shower. This is the darkest one I can recall:

{{gwi:1418874}}

But remember, this is all personal opinion. What you like? It's what you like. Don't be afraid to step outside of the design box.

Here is my black tiled shower for you to get an idea. I also have the same tile on the floor.

Baxter - the tile is beautiful. Is that Roca tile? Does it like like slate or chalkboard close up?

Thanks

It is American Olean Avenue One in Blackout. It looks more Chalkboard like than Slate. It has a bit of a textured finish. I spent many an hour looking for the right black tile so thanks for the compliment.