I think this little green number from Regeneration Tiles is great for a retro look. They are an unglazed porcelain tile, apparently wear really well, and are non-slip. They come in a wide range of colours and are a nice way to inject some colour into the bathroom.
These little mosaics are kind of cute too.
What about these black penny rounds? These would add some drama to a plain white bathroom.
Or then there's the white or marble mosaics in a brick pattern.
As for the grout colour - our architect has specified a grey/charcoal coloured grout. From a design perspective, the make the subway tiles pop, but it also happens to be a very practical idea as well. White grout always gets grungy looking over time (even if you are the type who likes to clean the bathroom every second day). Using a dark coloured grout will ensure your bathroom never looks dirty - even if it is! Luckily our bathrooms will be infused with heaps of natural light and have good ventilation, so mould shouldn't be a problem. Yep, definitely going with the charcoal grout on both the floors and walls.