Tyler Cowen (cited by Travis) quotes a NYT article:
. . . participants [at a retreat for autistics] . . . can wear color-coded badges that indicate whether they are willing to be approached for conversation.
and remarks:
I will be very happy if this ever becomes socially acceptable practice for non-autistics . . .
When I had a cubicle to call my own, I would sometimes put up a little sign:
CAUTION
TEMPORARY ACUTE SURLINESS ZONE
No one ever gave me grief about it, and I can’t recall that anyone even asked what it meant; I guess they assumed I was busy.
They probably were afraid of what your concept of a cute surly would be.