When you see a dog wearing blue gear—like a leash, harness, or vest—it often signals that the dog is a service animal or is currently in training. While there’s no universal color code, blue is commonly used for dogs that assist people with disabilities. These dogs should never be approached, distracted, or petted while they’re working.

Service dogs perform essential tasks for individuals with various physical or mental health needs, and interrupting them can compromise safety. You might also see therapy dogs or service dog trainees wearing blue, though it’s important to note that therapy dogs don’t have the same legal access rights as service animals under the Americans with Disabilities Act.

Not all color-coded vests have official meanings, but some general trends have emerged. Yellow often indicates a dog that needs space—perhaps due to anxiety, training, or medical recovery. Red typically means “Do Not Pet,” signaling that the dog may be working or uncomfortable with interactions. Green is often seen on friendly dogs who are still learning how to behave in public settings.

Understanding these colors can help the public respond appropriately to working or support dogs. By respecting the gear and space these animals require, we support their safety, training, and the well-being of the people they assist.