This basically means you can opt to wear a different coloured clip on your convention lanyard if you don’t want anyone to start a conversation with you (red), or if you want only people you know to start a conversation with you (yellow). Which would make sense for some people with particular social issues.
However, there’s a different colour for those who want to indicate that they’re happy for other people to initiate a conversation with them. Logically, I’d have thought that colour would be green for go – after all, cars move on green, pedestrians move on green, green is the logical action colour for most human endeavours.
But nope, it’s blue. I wonder why that is?