It’s the manufacturer/ suppliers fault not the installer. Who specified the tile? Where was it purchased? Unfortunately in most cases installation is acceptance, and that kind of tile tends to come out of the box dusty so the variation doesn’t show up until grouting.

Did all the boxes come from the same lot number?

This looks like different lot numbers.

Just to clarify ”installation is acceptance.” The installer has a duty to inspect the tiles before installation.

The installer’s failure to do that doesn’t mean you have accepted the job or limited your recourse against the installer. It just means the installer may have difficulty returning the tile as defective.

If that is freshly laid, the tile may change yet again when the mortar is cured in 2-3 weeks time. If it is not acceptable then, the only cure is a redo. Did your installer provide the materials, or did you? Floor and Decor?