Blue tiles often lend a cool, glassy quality to a room. I love, for instance, seeing crisp blue tiles against white cabinetry in a kitchen. Or sky blue wall tiles bringing a breath of fresh air to a bathroom. Here are some examples of what I'm talking about:
My favorite of all of the examples above is probably the bathroom in the second image. The blue is the only color in the room, and its hue here is just perfect. Used in a square tile laid in a running bond pattern makes it stand out as just a little different while also giving a nod to the very common brick pattern.
You'll find blue tile right at home in traditional rooms (image 5) and contemporary rooms (image 4) and everything in between (image 1)!