Porcelanosa tile are rectified, so 1/16th grout spacers will be used. I really like very small gaps between tiles, even on the floor, but that space will really depend on how good your walls and floor are. I know, tile setters hate big tiles, it's much harder to lay if walls or floor are not straight. So a lot of attention will be paid to prepare walls and floor to be as even as possible. Plus we'll be using unsanded grout with additive. I don't want to use too much of other colors, the tile itself is very nice. Since the room is very small we don't introduce a lot of color variations. We bought a few mosaic sheets, also from Porcelanosa, that has some light gray, white marble and crystal tile mix that will be used only in 2 big niches. We'll also thinking adding chrome trims between wall tiles, it looks very nice but Porcelanosa charges about $120 per 8', it's too much! I need to look online if I can find some less expensive alternatives.

It makes perfect sense to use a darker grout on the floor. And silver's genius. With regard to your question on vinegar, DO NOT use it on marble. It will ruin the surface. The acid will eat at the stone. :) Ask your supply store about a neutral pH cleaner they recommend. It'll help you keep the sealer intact for a longer time too!

This is a no-brainer for me - - SHOWER CURTAIN!!!! I LOVE the look of a traditional tie back fabric curtain on the outside of my walk-in shower with a mold and mildew resistant plastic shower curtain (NOT A LINER) inside. The fabric curtain stays beautiful and only gets washed once in a blue moon. The plastic (non PVC) curtains which I buy in Walmart for $8 get tossed out every 6 months. That beats the extra $1,000 for installing doors. I never have a problem with water getting on the floor. I simply have to make sure the plastic inner curtain is inside the base of the shower plate----just as I would have to make sure the shower doors were closed if I had doors. I can't stand shower doors. Mold builds up in the tracks or collects along the bottom even with frameless doors. Who wants to squeegee the glass doors and wipe them down on a regular basis? Not me-I often take 2 showers a day, especially in the summer.

For some reason several notifications popped up today that I never knew were on this thread or a couple others. I thought it may be helpful to some who may read through this (and reassuring to those who were concerned) to see in first two photos the watertight way the shower was structured, then in last two photos are the colors of grout/what I ended up doing (per my original purpose of posting this question on Houzz) : ^^^This red/pink stuff is the waterproof material that was put all over the shower/in niche/etc before the tile went on. And as I had mentioned in prior comments, a large curb was always the plan as you will see in this almost-finished photo :) *Note: The unfinished window is a reflection and not actually in the shower Finally, for those who looked at this thread in search for answers to their own questions about grout colors, I went with Tec Dove Gray Sanded Powergrout on the floor and niche (wherever the hex was), and Tec Silverado Unsanded regular grout on the walls with Powerboost added (to make the unhanded grout a form of Powergrout) on the walls...choosing the lighter gray to soften the bright white so that it would work better with the warm white vanity. The Powergrout has posed no issues whatsoever in the last month since the shower has been used. We did seal the floors/walls for additional mold/mildew/stain resistance. This is a good representation of what the colors of tile and grout look like in reality...the Dove Gray appears a bit softer in person though.