I do not have any tiles in my current house but if you think about grout discolouring and looking bad.... then I think that might answer your question. My thought - the less grout the better.

We are wanting to replace our splashback but we are not sure if it is possible....our current splashback is backpainted glass, securely glued onto the wall and a line of silicone sealing it to the rangehood - would removing it wreck the wall behind it? Would we need to remove the rangehood too and replace the Gib board behind it? If anybody has done this I'd love to know what is involved.

Can someone give me advice where I should start & finishes the tile on wall behind kitchen sink please? At end of bench? Under window finished edge or at edge of stone sink bench? See photo.

Eh ? You want white or off-white or similar ? Your kitchen is white and off-white , with quite a light wood . And a nice red toaster . I have noticed the toaster , and commented on it . You have purchased the toaster . Other people will notice the toaster , and comment on it . Because it is the only mildly interesting thing in the kitchen . Dark grey doesn't sound interesting , but charcoal does , so I am hoping it is closer to charcoal than dark grey . Am I overly optimistic ? Can you swap the dark grey for black gloss , because I suspect black gloss subways would look quite good there , and tie in the oven and cooktop too . Now what would happen if you were stuck with the grey or charcoal , and went out and bought a dozen crisp white subways , and a dozen Red subways . Get your 30 or so charcoal subways , and lay them out in a rectangle on the floor . Take 6 out in a reasonably random way , and put white ones there . Then take out another 6 , and put red ones there . Depending on the grey/charcoal , it may look crap , or it may look okay . If it looks okay , put the dozen grey ones on the top , take a few more away , add more red and white . Overdone ? Underdone ? Have a play . Don't like it ? Get all the grey ones , and 'stand them up' ( lay them vertically ) . Lay a line of red ones horizontally across the top , another line of white ones horizontally across middle . Swap them . Don't like any of them ? Get some brownish Tavertine Tiles , or an Orange ( or red or yellow or citrus green or your favourite colour ) glass splashback . Experiment . Put the on the bench and imagine . Thats what I'd do anyway . But I wouldn't do only dark grey , and I probably wouldn't do charcoal on its own , but I'd see first .