No to the grey - your wall seems to have a green tinge in them, so I would say either green/grey or a warm white tile with darker grout. If you choose the right grey/green, it is a classic look so shouldn't date. If you are a bit scared to choose colours, why don't you get a couple of warm white sample tiles and put where the splash back will go. You will soon see if it looks too stark....(maybe another idea, but possibly not a good one - why don't you see if you can put a few pages from a blank sketchbook in the whole area where the splash back will go (not super white white, but a warm white). That could also possibly highlight how stark (or not), the white may look. I can see what design tank is saying, as your cupboards appear to be more cream than white in the photos and if this is the case, then I agree the white will most likely look too stark. My cupboards in kitchen were white (but a warm white not a cool white). The stone bench tops also have the little speckles of stone in them..I can't remember the colour Ocean foam/Osprey.......but even with those colours and them not being cool whites, I thought the white tiles looked too stark against them. I therefore went for a glass splash back and ever since I then went to think of designs for my bathroom renovation, I constantly regret going with the glass in the kitchen and modernising the house too much..........definitely don't do glass if you are wanting to keep a classic charm to the house. In a long winded way, I think yes, I also think you should just stick with the grey/green. It will make a statement. Not the right shade...but another example....it may be hard getting the colour of the tile exactly right given that the walls are already painted and the tiles need to match.

Out of your selection - I would choose the middle one on the bottom row - it gives you a modern look and pattern without being too ghastly - it would fit in with the retro vibe as well. Good luck!

Although, I love soft, pale, barely there yellow, the canary (egg yolk as I call it) yellow is just too garish. I do like the mint green and I'm finding lots of sites that are showing myriad options in décor for it now. I imagine it's one of those "get it while it's hot" colors but it's a beautiful one to me. I've used the hot pink in much smaller doses for my daughter's room when she was little but I doubt I would use it in large quantities. I also deal with blue best in small doses.

always prefer Colorbond steel for a new home