The little guys are "peace and quiet" (green), "elbow room" (yellow) and "mingle time" (red).
Clever. Especially if you, like me, have a mood sensitive to people idling along side by side in small or large groups, stopping every two meters all through the maze-like store. (I'll admit, though, I'm quite good at cutting the IKEA corners and skipping past those numbnuts whenever I get the chance. It takes training.)