This is exactly why I love owning a historic home. I don't have to give a flying fig about trends. The classics never go out of style.
Subway tiles began in 1904 with the New York Subway. These lovely white rectangles captured the favor of, well, the entire world. They found their way quickly into kitchens and bathrooms. Back then, they used white in bathrooms and kitchens since it was easier to see dirt on white, and they were big-time germophobes.(Also why they had sleeping porches, but that is a whole thread of its own). Tiles then were 2 x 6; now you can get them in a variety of colors and sizes, but the effect is the same. New tiles tend to be too clean and white and original tiles were a more dull (same goes with hex). Back then, bathrooms and kitchens were sort of labratory-look (those crazy germaphobes had recently discovered the link between germs and diseases). Everything was white so it would be easier to see dirt, bugs, etc.
So, tell the trendsters to stuff if when they scoff at your "dated" subway tiles. What you have is a classic.
And for some lovely uses of subway tile...
A nicely done bathroom, though not completely "period." The white tiles are not at all boring. Look at the trim around the sink. This is very similar to the trim in my home, as Victorians really liked the non-mitered corner look. This is why you see a lot of corner blocks, etc. Later on with the conversion from gas to electricity, there was much debate as how one should properly illuminate a bathroom. I really adore those pivoting shaving mirrors!
I probably need to do a thread on hex tile. It is wildly popular now, but like beadboard, the modern versions are not neccessarily historically accurate (if you care about that sort of thing).
Hopefully some of these posts are somewhat educational. I feel the need to share a bit about the history of the products the trendsters are splashing around.