Thank you Bill. The Laticrete grout color our tile contractor is wanting to use is the "Marble Beige". That color is close to the darkest color in the tile. But there's not that much of that color so I'm afraid it would really stand out. I'm leaning toward blending with the "Sauterne". Everything else is either too brown or gray. Good to know we won't have discoloration or mold issues. Any recommendation on a cleaning product for our travertine? The travertine will be in our shower, knee walls and bathroom floor. He wants to wrap the knee walls completely with the tile instead of it just being in the shower and top of the knee wall. The knee walls are 41" high on each end of the vanity. Do you think this will look good? My plan is for possibly a very light quartz countertop on the espresso vanity. It's hard for me to envision.

Though you wrote that everything used was brass and copper, sometimes the tub spout nipple used is steel. SOMETIMES a tell-tale is if you hold the tub spout diverter up or flip the diverter lever to "shower", then turn the water on, is the water out of the shower head mostly clean? THEN divert the water to the tub spout and see if it's more discolored coming out of the tub spout. As to the valve itself being at fault, it'd be idiotic for a company to use steel in their valve. But anything is possible. If you have a any photos of the plumbing work before the walls were closed up, give them a look-over and check out all fittings, see if there's any iron/steel fittings in there. I know, I know. I'm just saying, you know? That issue addressed...most of what follows would be "whole house" symptoms versus just a singular plumbing run pumping out dirty water, or a singular fixture within the house that's pumping out dirty water. Any galvanized or iron pipe anywhere else in the house? If there's no galvanized/iron plumbing anywhere else in the house, then it could be sediment stirred up in your hot water heater, or it can be iron bacteria in your well. These can go unnoticed during normal use, but if a plumbing system gets shut down for a while they can show when the water again starts to flow. For sediment I'll usually drain, flush, and refill the hot water tank. Then remove any faucet aerators or screens or shower heads, and flush out all plumbing lines in the house. If it's iron bacteria, that's a whole new ball o' wax. If you have a rust-colored slime or coating on the inside of your toilet tank (not the bowl, but the holding tank) that's a good indication of iron bacteria. You can sometimes get an indication of the source if it's more "hot water centric" versus cold water centric. If hot water, it can be sediment or sulphur bacteria in the hot water tank that's been stirred up. Now with all that written? My first point of attack would be an errant piece of iron used when the bathroom was plumbed, I'd start with the tub spout nipple.

Why would vinegar darken the grout color itself? It might have removed what is a light colored effluorescence from the surface, often caused by too much water by the installer, and a common occurrence. Vinegar is a first chemical resort for doing that before hitting it with stronger acids manufactured by grout companies for that purpose. You do need to wait a period of time for curing so as not to break down the cementious material. It is not something you want to do repeatedly for that reason, early on or over the years. You might check over on john bridge tile forums. It is very active and run by pros who assist on all discussions. Show them some pictures. It's a very friendly and laid back place. A wealth of information. This post was edited by snookums2 on Sat, Sep 13, 14 at 12:58

Even later in this post and my problems continue. My question relates back to grout not being waterproof and it is expected that moisture will inevitably be behind the tile but not going past the kerdi. Above "Every grout manufacturer will tell you their grout is NOT waterproof. Tile is not waterproof. Sealer adds some measure of stain protection but is not waterproof either. Waterproofing is achieved by a variety of approved methods which fall into 2 categories; 1- Surface applied membranes such as kerdi, Hydroban, AquaDefense, Hydrobarrier, Nobleseal, Dalseal, Kerdi board and its competitor foam board from USG. 2- Subsurface membranes such as the classic vinyl liner WITH a moisture barrier behind cement board such as tar paper or sheet plastic. As a member of the National Tile Contractors Association, I can easily attest to the above information. But it's your shower and your money and you get to decide what you want to do." I have Kerdi board behind the tile so it is waterproof but the tiles continue to gray. I may need to redo the shower surround with different tile.