A friend mentioned this to me, I hadn’t heard of it. The Teal Pumpkin Project “Launched as a national campaign by Food Allergy Research & Education (FARE) in 2014, the Teal Pumpkin Project raises awareness of food allergies and promotes inclusion of all trick-or-treaters throughout the Halloween season.”
They seem to be pushing the allergy angle but a friend mentioned it in terms of diabetic kids that can’t eat candy. You can paint a pumpkin teal or just print out a sign but they also have a map you can register on so others in the neighborhood can find your house. They have ideas for non-food treats you can give out. Nice idea.