What about a muted wallpaper behind the new section that has both the old white and the new shade of white, without too much of a pattern so it doesn't fight the subway tile? Like maybe a vey subtle stripe?

Not a pro. You could try putting a divider in and going for a faux hutch look - since your backsplash doesn't continue you're halfway there anyway. Not sure what you have above but I assume the cabinets continue. So maybe just add a divider? Might look hokey, but it would be cheap to try. (Sorry didn't answer your question - I think pulling out counter and trying to do a piece of random counter would look a bit odd).

why not just remove the older portion and have it match the newer one? at least the transition will be way back in the corner.

Or, just have a piece of butcher block sandwiched between the two. It will be like a built-in cutting board

or get a piece of SS cut to fit over it

@Beth H. :YES. I like the butcher block idea.

How about replacing the newer portion with butcher block counter.

Love the butcher block idea!

Thanks for your responses so far. All great ideas. We were initially going to have a walnut countertop (mixed media idea with the wood and quartz, but opted for a full quartz look. We were concerned that the countertop would stand out too much and didn't love the fact that it won't have lined up with the cupboards above.

Does anyone know if there is an issue with the new part being removed/cut from the old part? I can imagine that there would be some stress oh waterfall joint, but if done by a pro, it can actually be done?

i can't even see the uppers.

post a pic that shows everything.

you want a fix for the two diff colors. sticking in a piece of gray quartz between the two will look worse than a wood butcher block. you can get a wood stain in any color, so that shouldn't be an issue.

or do the SS.

Or, have the old portion redone w/the same material as the newer part.

don't understand what you really want. nothing is going to be exact unless you replace the entire countertop.

pick your poison

It can be done (but not as easy with quartz). You need a pretty skilled craftsperson for that. Here's the problem: Finding someone who will do it. At least in our area, it is hard to find a company that will work on modifications of solid surface countertops that are ALREADY installed. We get several calls per month from homeowners who want a countertop cut to accommodate new appliances, or a hole drilled for a new faucet/soap dispenser, etc. Most countertop fabricators won't do this work on already installed surfaces, and so tile and stone contractors (think "tile setters") with the tools and skills get the calls. Two problems: Liability of working with a large, installed surface that likely cost $$$ for a $ job of a few hours. If something was to go wrong (piece fractures, chips, etc, and more likely with quartz), who is liable for the $$$ countertop? Secondly, most of us are very busy with our primary work, tile projects, and these projects are generally of a significant scope and duration. It doesn't make business sense to pull someone from these primary projects to go handle a little "fix" somewhere for a customer that we do not have a relationship with, and with the liability attached. I'm just sharing the reality based on our experience. Obviously, if the company that installed your countertops is willing to do this, that is your best bet. Beth's idea of butcher block is a good one but not easily executed on an installed surface. What about getting a butcher block cutting board that is cut to size and setting it on the countertop as a much easier second option?

This is the fabricator's fault. Not for poor workmanship, but for failing to tell his customers "No." No way should an experienced fabricator seam two mismatched colors together. No matter how much the customer insists and waves money about. Sometimes you have to save people from themselves. He failed miserably.

To Dragonfly's point, I drilled a hole for a hot water dispenser, used the wrong bit, and buried a band of brazed diamonds into the biggest island I'd ever worked on. I was able to drill it out, but not until I chattered the new diamonds across the top. Fortunately I got both fixed before the customer knew.

That island would have been $4,000.00 to replace minimum. So I bet $4,000.00 for the opportunity to make $250.00 in 5 minutes. That's a foolish bet and I'm pretty good at this.