Looks like the "seams" or "lineas" are what draws your eye to it.

No fix for that other than remove & replace.

I would be very unhappy with that - looks horrible.

The remedy is to make the installer replace it so it matches. That is awful, sorry.

Worse yet, what if your fabricator can't find material that matches the rest of your tops? Will you accept a brighter white splash? He may have to replace the whole kitchen. In fact, he may know this which is why he tried the mismatched piece in the first place.

How much do you owe him please? I could shove a coffee pot in front of that mismatch for a 50% discount. He may snap up that deal if complete replacement is the alternative.

How many slabs of material did you buy? If buying slabs for optimum seamability, you will buy more than for optimum yield. If that little bit was all that came out of a second $4500 slab, and your counter was $4500 more, would you have still paid that?

If he couldn't accomplish that long backsplash with one slab, then there should have been a discussion about using 2 book-matched slabs with a seam in the middle of the backsplash.

Thank you all for the replies. We paid the fabricator around $14k to do this work and provided 6 jumbo slabs of REM to do the whole kitchen, we were very disappointed to see this result. We will ask them if they can replace the small white piece in the backsplash with another piece of stone which matches the same color, let’s hope it goes well