that is not charcoal grout

this is charcoal grout.

Unfortunately, yes it is. It started out darker but keeps getting lighter over time

lets see the bag it came in

who grouted? how much water was used? does the entire floor look like this?

using too much water to clean up excess grout (during the process) will dilute the dark colors

when you say it's getting lighter, how much time? what are you cleaning it with?

lets see the entire floor and lets see the product used

yep. probably dust, face powder, etc. what happens if you scrub it?

Here’s the grout used...was done by the tile installer

Some areas are lighter/darker than others

I tried scrubbing with water/tile cleaner using a toothbrush but no real change

that's the same brand and color I used on my black tiles.

since you prob didn't see your install guy, I bet he used too much water.

do some of the joints seem a bit powdery or loose to you?

Grout discoloration can occur when you add too much water to powdered groutduring the initial tile installation. Improper cleaning of grout haze from the surface of the floor or wall, or failing to let the grout cure for the amount of time suggested by the manufacturer, can also lead to uneven grout color.

with dark grout, you have to be very careful during the wash/clean up phase of the grouting process. too much water on the sponge and it dilutes the grout too much, to where it lightens. I'm also positive it what happened w/yours.

This is directly from their PDF format on grouting:

1. Dip the sponge in a bucket of water and wring out the excess, so that the sponge does not drip water. Using very little pressure, pull the sponge diagonally across the grout joints to remove the excess grout from the tile surface. Also use the sponge to smooth the surface of the grout joint. Turn the sponge over and make another pass in an adjacent area. After using both sides, rinse the sponge in one bucket and wring out the excess water. Dip the sponge in the second bucket of water, wringing out the excess and continue the process.
2. Change the water in the buckets frequently to help limit the amount of haze that forms on the tile or stone surface.
3. To prevent discoloration and soft/powdery joints, avoid cleaning with excessive water.
4. To control color variations, buff the grouted surface with cheesecloth or a clean, dry cotton cloth when a haze is visible on the tile surface, usually 30 to 60 minutes after grouting. This should remove any remaining surface water or grout residue.

https://www.johnbridge.com/vbulletin/showthread.php?t=125443

Grout turning white is usually due to efflorescence, which the movement of salt or minerals to the surface of porous material (such as your grout) and forms a whitish coating. ... Another possibility is that grout containing polymer was used and exposed to too much water before the polymers had a chance to combine.

Again,,,too much water during the grouting process

Is your entire floor like this?

Thank you for that detail! My entire floor isn’t this light...there is some variation. Do you think there anything I can do at this point?

you can try using a sealer that enhances color. it might darken it. (don't use the sealer if you r going to try and stain the grout! The sealer may repel the grout colorant. try the sealer in a small place out of view and see if it darkens it. just do a small spot. if not, go for the colorant.

Or, match the good portion of the grout w/a grout colorant.

Grout Renew is one that may work for you

(Mapei has one too,,,maybe stick w/the same company?)

ya know, you might want to inform your install guy of what happened. If he doesn't know, he should be informed.

And he should come over and do this for you

Thanks, have you used either of these products? I was looking at them as well but the reviews are mixed, with the bad ones being really bad (like destroyed the tile bad)

depends what the tile is.

yours is porcelain? shouldn't do anything. Natural stone would be a problem.

use a paint brush very carefully.

and no, I have not.

Another option, scrape out all of the grout at least 2/3rds, and re-grout, following the instructions not to use too much water.

Have you called your tile installer? He's the one that should be rectifying this problem. Any tile installer worth two cents knows that dark colors dilute w/too much water.

Thanks, unfortunately it’s natural stone. The tile guy was a pain in the ***, so I hesitate to ask him anything at this point. I’m sure he’ll argue he did it 100% correct :(

Black sharpie? Kidding... maybe not kidding ;)

sheesh. up to you what you want to do w/him. I'd at least inform him of what he's done.

natural stone as in what? basalt? since it's already black, it shouldn't be an issue w/staining. (carefully seal only the tiles themselves before trying this stuff)

try the product in a corner somewhere.

use a very small paint brush and carefully paint the grout. Total PIA, but it's how you'd have to do it. Don't know if you then seal it, or what cleaners need to be used.

In short, there is no way it's going to turn back dark naturally or by using some cleaner. It's possible an efflorescence remover could work, but since this occurred during the grouting process, I'm thinking that ship has sailed.

black sharpie could also work. you'd have to do every joint to get it to match.

the grout staining stuff is basically the same premise.

after care is more of a problem. like I said, check w/the grout stain specs and see if you can seal it afterward, or what cleaners they recommend.

I use this on my marble

Issue will be now is you scrubbed it and attempted to clean it. Even if you did not hurt it in any way you just gave him an out. Should never touch someone's work until you are satisfied they are done, done.

We tried the Multicolor Plus FA on sample tiles. Used several colors. ALL turned MUCH lighter than pictured. And yes, we followed the directions to a "T" because we are OCD. So we gave up on that line. Used the Flex Color CQ. Perfectly matched the color on the outside of the bag. No mixing. No muss. No fuss. So you probably mixed it correctly but that stuff is notorious for going much lighter than the swatch on the bag.

Flexcolor CQ is a great way to go.....also "Prism" grout from HD.

Stonetech - do you know anything about the SimpleGrout Ready to Use by Custom Building Products that HD carries? Some people say it leaves a yellowish film that doesn't come off and changes the grout color yellow.

No, "Simple Grout" is for simpletons. They try to imply that "Simple" is good. It is the lowest common denominator as far as grout goes. Use Prism, CQ or Fusion Pro.