If you can't source them consider reusing the tiles behind the sink and in their place get a larger mirror

Many thanks for the links Carol much appreciated x Your 1st link is the same tile that pops up at a number of places including Tile Mountain where I 1st saw that tile and its not quite what I'm looking for. I think I have seen the tile in your 2nd link before as well - its one I'm keeping on my possible list - its not exactly what I'm after but reasonably close.

I would suggest white or pink. By white, there are so many different shades of white that you could choose,. Here’s some ideas. The last ones have a lovely hint of blush pink without being Barbie.

My grandparents had a suite this colour and then plain small square cream tiles with a black border tiles. I remember it looking utilitarian and to avoid that I would choose a heavily patterned, luxurious feeling white marble style with a gold vein. Alternatively a coloured marble could look opulent- see if you can find a lemon marble or a green marble you like against this suite. And I agree that some of the wall panels are fabulous