If you’re out for an evening stroll or taking your little one out for trick-or-treating this Halloween, you might notice a peculiar addition to the traditional black and orange decorations synonymous with the fall holiday: teal-colored pumpkins.

While they might stick out like a sore thumb, the teal pumpkins actually serve a very important role for parents and guardians of children who suffer from potentially life-threatening allergies.

Teal is recognized as the color associated with food allergy awareness, and for the past decade, parents have been painting pumpkins teal to signal to trick-or-treaters that their home has safe alternatives for allergy sufferers.

Known as the Teal Pumpkin Project, the initiative was started in 2012 by Becky Basalone, a mother in East Tennessee whose son suffers from severe food allergies, according to Parents.com.

Bassalone’s family put a teal pumpkin outside their home and offered allergen-free candy alternatives like toys and other non-food items for trick-or-treaters.

“When our neighbors and trick-or-treaters approached our house on Halloween night, the kids would see the teal pumpkin and my son would proudly explain his food allergies to them,” Bassalone said in an interview with Allergic Living. “It became a source of pride and a way of starting the conversation. By the end of the night, the kids were more willing to dive into the bowl of food-free treats than the candy.”

She shared the story online with a food allergy support group and her little grassroots effort caught on like wildfire, eventually being adopted by Food Allergy Research and Education (FARE), which brought the campaign nationwide.

With chocolate and nut allergies being among the most common food allergies in the U.S., many young trick-or-treaters have to be on high alert about potential exposure.

Those teal pumpkins now signal to parents that their home is inclusive to allergy sufferers or kids with dietary restrictions. Many homes that participate in the campaign offer things like glow sticks, art supplies or stickers instead of traditional bite-size candies.

Bassalone’s pet project has become so widely accepted that many retailers sell teal pumpkins alongside regular Halloween decor, and FARE provides an online map for homeowners to identify their house as allergy friendly and help families plan their trick-or-treating route.

“What if we could make it so kids with food allergies can enjoy Halloween with their friends, including going door-to-door for treats?” FARE writes on its website. “When you offer non-food treats, more children get to enjoy Halloween without fear.”

For more information about the Teal Pumpkin Project, click here.