We are using wristbands as a way to signal that you're open for a chat, as well as make it safe to say "I'm busy" or "I need a few moments to myself."
We'd like to give you the control to turn "on" or "off" from conversations -- as you see fit or feel ready. This is sort of like muting the world away in Slack, and taking a few moments to be heads down. By giving you more control over social interactions, we hope you'll be more comfortable connecting to other folks during the event.
These wristbands have two sides. You can turn your wristband to yellow for "let's chat!" When you need a break, you can turn it to black for "I need a few moments to myself, please."
You can pick up a wristband when you first arrive at the event, and read more about this idea here.