3/8" is ridiculously wide for anything other than large handmade tiles. A blanket statement? Youbetcha. My opinion? Most certainly. That's coming from a guy that prefers 3/16" grout lines as typical. The only reason I could ever think going with a 3/8" grout line was if the layout dictated it. It allowed them to fill the space using full tiles all the way across the floor. No cuts. More efficient use of materials. But man oh man...I'd certainly ask first before just going ahead and doing it. But on that same note...these things would have been taken into consideration during the planning stage, well before any work was started. Is what you have typical? I'd say no. Does it fall under the realm of "acceptable"? If it wasn't spelled out in the contract, then unfortunately, I'd have to say it does.

Yvette Im sorry your upset, It does look lighter in todays photos to me. You have very poor photo quality and in truth you are comparing a Showroom floor with white marble or glass contrast relfecting and a complete different lighting schematic to your tub alcove. There is some solice in lighting. This is repeated on these forums time and again. Stone itself comes in dye lots and VERIES drastically. Stone wicks moisture, from thinset substrate and grout as it cures it gets darker before it lightens. Some thinsets can take 30 days to fully cure, some portland grouts do normalize over 7-10+ days. and there is a dozen things that can go wrong with hand mixed and installed grout. I cannot see close enough the details of your install but I can tell you I have had to watch sales people at tile shops like a hawk in that they are usually not a person to take advise from. Can you be 100% certain they sold you the proper color/brand or did they sell you something similar to sell you something. ? You should have more recourse if you Payed a tile professional to source and purchase the materials themselves grout included and if you have a contract and stayed hands off. One thing homeonwers dont consider when they get involved with these things is the importance of putting all the liability in the contractors hands to afford recourse. People that do the shopping finding deals choosing materials, and then hiring labor have little to no recourse so i hope thats not you.. I suggest further patience and see how it lightens, play with lighting and start to focus on other aspects of your room..

He is no tile pro. Or anything else. You knew that. You still hired him. From this, it’s doubtful that he got the new to him system done correctly either. It’s not just the grout.He is clearly out of his depth on any tile job.

It was done in August...lol. We're still trying to work out all the problems. They tiled on top of bowed studs. They mixed unsanded and sanded caulk in joints. The caulked in the wrong color. They grouted in the wrong color. They grouted in change of plane joints. Grout chunks and caulk were smeared all over tile surfaces. Bright white adhesive came up through the penny mosaic tile shower floor grout. This was new construction - so 4 full bathrooms with at least one of these problems. Most recently they recaulked with SPECTRUM brand caulk that was supposed to match ColorFast CUSTOM brand caulk. NOT EVEN CLOSE!