Usually, we see a bathroom like a very light space, yet sometimes it could be better to use some darker colors, for instance, to use dark tile in the small bathroom.
Let’s say, you don’t have to make all the bathroom space with dark tiles although it is also possible. But it is much better to add some dark tiles into the generally light picture, or maybe you can combine darker and lighter tones of one color to play with such difference. The idea of using dark tile in the bathroom may be helpful in making the space visually bigger playing with the contrast of dark and light: you may highlight the space by making shower booths dark while all other bathroom walls are light.
It is not necessary to create your own ideas about bathroom design, because nowadays there are now so many various magazines with great and professionally done pictures of bathroom design. The Year 2020 collection: