Sorry to hear this has happened, you have to be so careful and check everything now but would have though batch numbers would be one of the top of the list jobs because even if all mat or gloss could have been different shades
But maybe as he did not supply tiles, did not think his responsibility, which is true but thought would have checked out of habit, especially the diy stores, even if all boxes right often odd wrong batch tile fitted in box, to many sheeple running around store ,removing and putting back elsewhere
It is a matter of gritting your teeth and starting again
Or
Lighting is so important in rooms ,maybe a few well placed up lighters with good quality dimmer unit, keep curtains drawn, using your partners migraine as the reason or maybe some floor paint, believe Home base doe’s this, maybe a few well placed rugs
Seriously the rest looks great, you have done a really good job, I would be gutted but even more reason to take up and redo correctly