That’s what you’ve got, and you want more of it? And you are not the one who installed it. The sort of good news is that you are unlikely to find matching tile and now get replace this with tile that reflects your own choices, not someone else’s. That can be a good thing.

If you want replacement tile recommendations, could you give us more images and explain why you need more tile?

The microwave in the kitchen needs to be replaced with a much slimmer microwave that will leave an area between the stove and the microwave exposed.

Im not sure if you can match that. In the meantime, you can remove it all and just keep the short backsplash that matches the countertops. Of course, this will require drywall repair or replacement and painting. Or, maybe just paint that gap the same red as the kitchen.

That looks like tumbled marble interspersed with ceramic pieces. Can you not just paint the gap a charcoal color?