So the inside of the shower has the little gray tiles and the outside has the big gray ones? I think it would look weird to have a white stripe in the entry threshold (if that's what you're talking about). Anything that could be walked on should be gray.

If it's inside the shower like a bench, then the wall color would be good.

Curb. That's the word!

If it matters, where I live, it is common to use tile on the curb if it's being used elsewhere. Solid surface tends to be slippery and people WILL stand on it.

Sophie, what is the issue that you’re seeing? Why will it have leaking problems?

Incorrect waterproofing.

Sophie, would you mind elaborating so I can take up the issue with my contractor?

Thanks, Fori - I think I’m leaning toward the taupe tile on the curb.

Post pictures of the in progress. Starting with the bare studs.But right now, the walls are not waterproofed. And that curb is a disaster waiting to happen.

Sophie, I don’t have pictures, but they started with black paper, then the cement board, then the tile.

I'm far from an expert but I am currently remodeling and I believe there needs to be waterproofing of some kind between the cement board and the tiles since tiles are not waterproof and cement board absorbs water. In my remodel, there was red guard applied on top of the cement board and then the tile applied over the red guard.

The black material is water proofing! Have them tile the shower pan before finishing the walls. The wall tile should sit on the floor

No, it's not. It's tar paper, which is a vapor barrier

I forgot to mention that they hot mopped the shower pan and the curb to water proof it.