It SHOULD even out by the time a week is up. MAX.

Bill, I wish you did work in California! It's still looking a bit uneven and my contractor doesn't have a lot to say about it. I'm ready to hire a grout doctor to re-do at this rate.

Should a sealant change the appearance of the grout to any extent?

Depends. An enhancer will. A standard penetrating sealer shouldn't change the look at all.

While this comment arrives too late it is helpful for future reference. I cleaned my vanity top so it was a consistent color. After 3 attempts to spray a sealer the tgrout dries inconsistently with light and dark runs., evidently a cause from the sealer itself. I will continue to spray the light runs of grout after trying to scrape those areas with a flat nose screw driver Then spraying again and hoping it darkens with another application. I had a company ruin my terra cotta tile floor by not only creating inconsistent coverage ( that’s the only way I can desribe the problem) but also by the worker not properly wiping the sealer off the surrounding tile. He had to sand the sealer off.

one of the best and easiest ways to clean grout is scraping the soiled top layer of grout off with the appropriately sized flat nose screwdriver. Not as difficult as you might think and it gives you a fresh surface to work with. There are dealers that will target the grout itself while evaporating on the tile surface itself.

It should within a few days. Either way, nothing you can do now but wait. let me ask you -- was this an aerosol sealer?