I went vertical so tall. Helps to raise height. It will also match your 300 floor tiles I have silver grout with antique white tiles. It’s a personal choice you can’t go wrong either way.

Where horizontal and vertical meet should not be grouted because it needs something flexible, something we learned the hard way, twice, in different houses. Make sure your tiler redoes the waterproofing properly too.

If you're wanting to recolour tile do NOT do this yourself. If that's the way you want to go get the pro's in. They do not use paint, they use an acrylic resin and chemically etch the tile before hand. It is applied with a spray gun for a nice finish. It won't last forever but you will probably be satisfied with the results for long enough.

Hi Angel, because you’re only after one tile, it’d be worth a call to some of the companies that specialise in vintage / retro capping tiles as, unless they have large numbers, they often have stock not listed on the website. Alternatively, Schots have a very similar shaped tile, which they call a dado tile and tile paint is much improved, so that may also be an option. Good luck