For centuries, hand-cut mosaic tiles called Zellige (also Zelige or Zellig), made from a particular clay mixture found in Morocco, have covered walls, fountains, swimming pools, floors and even more so in the western Islamic world. And recently, secular decoration – probably a derivative of Byzantine mosaics – is experiencing a resurgence across the world.

But in its latest incarnation, the Zellige tile trend is moving away from the traditional mosaic and into monochromatic territory as designers apply shimmering surfaces of a single glazed hue to surfaces in kitchens, bathrooms, and more. .

“The glaze, color and imperfection of Zellige tiles evoke their handcrafted quality,” says AD100 designer Nicole Hollis, who wrapped a bathroom in her own San Francisco home in a turquoise blue version of Key. “I prefer to use just one color in the showers,” Hollis adds. “Because the enamels are applied by hand, no two tiles are the same. This creates a watercolor effect. The varying thickness of the tiles only adds to the drama.

Precisely, this look – in a rainbow of hues – has infiltrated a lot of homes designed by AD100. Recently used ASH NYC tiles (also from Key) in a powder room in Tribeca. Giancarlo Valle used creamy sides of it (on fireplaces, sinks, and bathroom walls) in a colorful Manhattan townhouse. And when the time came for Clements Design and Waldo Fernandez to design model Kendall Jenner’s pool tub in Los Angeles, a bunch of mosaic tiles were created by Badia design.