Sadly nowadays everyone seems to blame the trades man . I've had same batch tiles that have still been different colors . If you have had the timer in to measure up the area when quoting then the amount of times plus wastage should have been bought ,
Who ever purchased the tiles should have checked batch and shade codes match up , weather it was on Del of tiles or when in stock in shelf . Then when the installation starts they should have been checked again , then shown to customer but tiles were short to start so the job should not been started , unless the customer understands there is a chance additional tiles might be different . It may now be hard to source matching tiles to original ones . So really there are at least 5/7 checks before starting but the end responsibility is with who ever bought tiles . I normally wooumd change few tiles like this above if new tiles can be found that match as a good will gesture as good word mouth advertising is supberb and customer could say a great job and explain how the tiler even came back to change few tiles of different color for us . Then everyone sort of comes out of this this without much cost lost . The owner then could also give hand cleaning up old tiles and offer something as a good will gesture for additional time for tiled and , then customers floor looks fab as it should have done . Sadly though jobs like this never seem get sorted that easy