ᐅ Tiling work unsatisfactory – grout color inconsistent

Hello everyone,
our house construction is in its final stages. Completion is scheduled for just under a month from now. So far, we are very satisfied with the construction company and the site manager. Since we have little knowledge about building ourselves, we have been accompanied by an independent building inspector from the beginning. This has worked very well so far.
Now the tiles have been installed in the bathrooms, and this is the first time we are experiencing real disagreements. We had quite a few complaints. Some tiles protrude too far. In my opinion, the grout color differs too much in some areas. Some grout is already crumbling. Our site manager met with the tiler, and their conclusion was not really satisfactory for us. They want to replace one or two tiles, but otherwise claim everything is within certain tolerances. We do not want to accept this that easily and plan to review the matter with our building inspector. However, I would be interested to hear opinions here. What is considered within tolerances and what is not? Attached are a few pictures.
Many thanks

The tolerances are quite well designed for the tiler. We had several issues with it ourselves. The grout lines can be easily repaired.
We also had the dark spots, but they disappeared after a few months.

What kind of tiles are these? Each tile has a different pattern? I would also criticize that two identical ones were placed next to each other. But I can hardly tell. Photos with a scale would be helpful.

This is simply poorly done; nothing should be crumbling like it is in the pictures! You can clearly see that...

Joints must not crumble; there are no tolerances for this.