Mrs D-- I know I already answered you by email, but for the benefit of those searching the thread-- I'm not familiar with power grout. Not because it's not a good product (TEC has a terrific reputation), but because there are no distributors up here, unless you have a show room. That said, if your installer says he can do the installation without scratching the stone, I'd take him at his word. As for the sealer, personally, I'd prefer to seal it once-- when everything is done. Whichever way your installer wants to do it, I'd go with his recommendation. Some would rather seal twice, others all at one time.

Please disregard - expert advice received on the Bathrooms forum. (posting so that the thread on this forum can move down, and also so that future Google searchers potentially pulling up the post will know on which forum the answers can be found.)

I like the matchy grout. Here is why: Autumn dot 4's kitchen is by far, my favorite GW kitchen and I do not handle change very well. Seriously though, instead of envisioning just a backsplash, look at your kitchen as a whole. The tiles themselves are unique and gorgeous. There is no need to individually define each tile. With 2x6 tiles, that will be a lot of grout lines. I think you need to go subtle. Do I love the inspiration picture? Yes. Do I think that would work in your kitchen? Yes and beautifully so. I just think the other is better. Disclaimer: I have gone terribly wrong with grout choices in the past so you may need to heed the advice of the experts and ignore mine.

A high performance modem grout is a lot more expensive than the old sanded or I sanded grouts. For a reason. Technology. Choosing a cheaper product, and the wrong product was an error. They should have discussed this with you, given you the change order upcharge, and used the top quality product. You wouldn’t be having this issue. Installers used to old fashioned grouts don’t like it, because it’s more work and requires a helper to be sure it’s cleaned in a timely manner. So it’s an upcharge on labor as well as materials. But it’s a once and done. https://www.lowes.com/pd/MAPEI-Flexcolor-CQ-1-Gallon-Cocoa-Acrylic-Premix-Grout/50360276 You can still go over what is there with a colorant. But only provided that it’s steam cleaned of any of their “cleaning” residue, , allowed to dry, and there is no grout loosening or coming out of the joints. You have to wipe it with a clean white rag and make sure there is no residue coming off after cleaning. That would indicate an improper mix with too much water in it. https://www.lowes.com/pd/MAPEI-Grout-Refresh-8-fl-oz-Cocoa-Ceramic-Porcelain-Tile-Grout-Sealer-Squeeze-Bottle/999977878