Literally, it's highlights with a sponge. It's a new emerging trend that's just barely started in salons, but pretty soon it will be the buzzed-about technique. "It’s a form of hair painting," Kair said. "You apply color with a sponge and it just touches the surface of that hair, so you’re not penetrating it." The effect is sunkissed, barely-there color. We think this trend has DIY written all over it. Every kitchen has a sponge, right?