Tiles and borders

[Yorky]

Saw these tiles in B&Q this afternoon and these border ones
Would the silver border tiles look OK about waist height around a small bathroom, and does it matter if they aren't the same length as the main tiles? I'm thinking matt white, but not sure how much it will annoy me with the ends of the tiles and borders not lining up.
Would you have the border and plain tiles, or a few of the accent tiles as well?

Thinking of a dark slate floor, if that makes any difference

I like the border tiles, they could look really stylish. I think it would annoy me if the tiles and the border were not the same size so I would probably look for something the same size. If you keep it simple then it will never date and you can update with accessories as your mood takes you. Black slate would also work really well.