Should the grout be the same color? Not necessarily. Will it look weird to use a darker gray on the floor and a lighter gray in the shower? Not at all. Any recommended colors for the shower and floor tiles along these lines? I've been getting stuff at Lowe's and they carry MAPEI Warm gray for the subway tile, and silver for the hex, if you lke a darker grey for the hex. Silver is actually a medium grey, but it'll appear alot darker with the white tile. Our bathroom isn't perfectly square. I think a colored grout seam that is uneven will be really obvious(that's my understanding where you would do any flubbing). Can you grout just the seam white? Can you skip grout and caulk it? Any suggestions here? Grout everything on the floor the same color. it'll actually show up more if you try doing what you suggested. It'll literally draw attention to it. What you want to dpo is make sure that you're square to the most obvious walls from the door. Especially with the hex, it won't be quite as obvious as you think, unless it's WAY out, and then nothing you can do will hide it, even using a blending color grout. One other thing-- that joint where the floor hits the walls should be caulked, but still caulk it with a caulking that matches the grout, both color AND texture. Does anyone know what the measure is for hex tile and subway? For subway, use unsanded, and for the hex, use sanded.

Sure, when I used to use CPE/Noble/Oatey/CPVC, I wrote about their membranes. Matter of fact I still write about them on occasion, but much less on this forum. We've had a slew of threads about PE behind cement board shower construction. If a DIY wanted to try floated mud walls, we'd write about those as well. But it's not generally a DIY-friendly method. When I used Wedi years ago, I wrote about Wedi. When I used Kerdi, I wrote about Kerdi. I prefer cement board over fiber-cement 95% of the time. I prefer fiber-cement over cement board 5% of the time. Each works better for me in certain circumstances. I do think that for moisture control, a topical membrane shower is superior to a membrane buried within the shower wall or buried in the shower base. I don't want cement board walls or presloped mud bases getting wet. I build fairly tight houses, and moisture control is important to me at each and every location in the house. A major point for me is I don't use foam presloped bases. Most every shower is a custom size so packed deck mud works best for me. Wedi told me "...our shower is all inclusive, you use all or none." Kerdi said "...sure, use our foam base or use the membrane over deck mud." I settled on Kerdi as being the membrane for me. Unlike RedGard, it works as a shower membrane and as a steam room membrane. I prefer easy 100% coverage of sheet membranes versus the "I hope I didn't get any pinholes" roll-on membranes. And that's my personal limitation, my personal concern. Kerdi is readily available at the retail level in my area. Kerdi is easily transportable. If Wedi would improve their distribution network they'd make inroads into DIY residential showers. They'd take market share away from Schluter from the builder side of it as well. And there is the big difference. A builder who is set on a product that works for that builder is going to use that product. A DIY person, which is what this forum is geared to, needs to have a retail distribution network in place so they can access these products at the retail level. All this relates to how I build and how the product works for me. So yes, more often than not I do Kerdi showers. If a Wedi guy, or a CPVC guy, or a Kerdi guy, or a floated mud wall guy wants to post, have at it! Heck, how often do I hear about hot-mopped pans on this and other forums? Do I ridicule them? Not at all. It's a regional thing, and I respect that. All are welcome.

If the tile is "unfinished" than you would want a sealer on it. However, if it is unfinished than the tile sealer should have been put on before the grout went on as grout can stain an unfinished tile. If the tile has a finish than a sealer is not needed or necessary and I'm not even sure if it will "stick" to the tile. You need to have this answered by Bill Vincent or one of the other tile experts. If you post this on bathrooms and/or flooring forums, he and others who do tile installation for a living, will see it and be able to give you a better and more thorough answer than I.

i'm not sure if this will help but could it be that the water you're using to mix your grout has a lot of minerals in it? same thing for the water you're filling your finished bowls with? i'm wondering if what you're seeing isn't grout at all, but minerals that have settled (which would show up a lot against black grout.) i'd try mixing the grout powder with filtered or bottled water, in case that's the problem. maybe try filling a finished bowl with that, too, just to see. the water in our last city was extremely hard and my black grout would turn light gray upon drying. once i switched to filtered water, my grout stayed dark.