Dogs have long played a vital role in human life, serving not only as companions but also as highly trained helpers. In modern society, we rely on visual cues—particularly the color of a dog’s vest, harness, leash, or bandana—to help identify the purpose that a dog is serving. While there’s no single, legally enforced color‑coding system, certain colors have become widely recognized. In particular, blue gear is often associated with service dogs or dogs in training. These visual signals help guide public behavior around working dogs: by noticing the color, people can better understand whether a dog is “on duty” and should not be approached or interrupted.

Blue gear most commonly signals a service dog or a service dog in training. These are dogs that perform essential tasks to assist individuals with disabilities—such as guiding visually impaired people, alerting to medical crises like seizures, or helping with mobility. Because these dogs’ work is critical and often life-saving, it’s important for them to remain focused and undistracted. The blue color serves as a cue to the public: give space, don’t pet, and avoid interrupting. For dogs still being trained, blue gear functions similarly to a “student driver” sign—reminding people that the dog is learning, and that maintaining a calm, consistent environment is important for its development.

Sometimes therapy dogs also wear blue gear—but their role is different from that of service dogs. Therapy dogs provide emotional support in settings such as hospitals, schools, or care facilities. Unlike service dogs, they do not have the same legal public-access rights under laws like the Americans with Disabilities Act (ADA), and they may only enter certain places by invitation. Because blue is used by both service and therapy dogs, it’s not always clear-cut what kind of support animal a dog is. That’s why it’s respectful and helpful to observe for additional identifying patches or, if unsure, politely ask the handler before interacting.

Blue is not the only color signal you might see on working dogs, and understanding other hues can further improve interactions. Yellow gear, for example, often means a dog needs space: it could indicate anxiety, reactivity, or ongoing training. The “Yellow Dog Project” promotes this as a way to raise awareness. Red gear usually means “Do Not Pet,” signaling that the dog is working and interruptions could be disruptive or dangerous. Green gear is sometimes used for dogs that are friendly or in early-stage training; it suggests interaction might be more acceptable, but still warrants permission from the handler. Other colors like orange or purple might denote specialized roles (e.g., detection dogs, emotional support), but because there is no fixed standard, these are less predictable and vary by organization or individual handler.

Why does all of this matter? Because working dogs play a crucial role in helping people live more safely and independently. A moment of distraction—someone petting a service dog, calling out to it, or offering treats—can interrupt its concentration and cause a real problem. By paying attention to the color of a dog’s gear, people are better equipped to behave appropriately: not touching, not talking to, and not feeding the dog unless invited. It’s also helpful to watch the dog’s body language—if it’s tense, focused, or ignoring overtures, these may be signs not to interrupt. Teaching and practicing this etiquette helps create an environment of respect that protects both working dogs and the people who depend on them.

Importantly, though, it’s critical to understand that there is no legal requirement for service dogs to wear a vest or for that gear to be any particular color. Under the ADA, service dogs are defined by what they do (the tasks they perform), not what they wear or what color their gear is. This means a working dog might not be wearing anything that signals its role, so the absence of colored gear doesn’t mean a dog is not “working.” On the other hand, just because a dog has blue gear doesn’t guarantee it is a certified service animal: sometimes owners choose blue simply for personal preference.

In short, while color-coded gear for dogs isn’t regulated by law, it has become a powerful non-verbal communication system. Blue gear most often denotes a working or service dog (or one in training), with the public expected to avoid distracting the animal. Other colors—yellow, red, green, orange, and more—carry their own commonly understood meanings about a dog’s behavior or role. By learning to interpret these cues and respecting a dog’s space, people can support the important work that these animals do. Gear color is more than just a fashion choice—it’s a signal of responsibility, focus, and trust.