“Tyre Yellow” → maybe a yellow toy car/robot wheel (tyre) used with DC or TT motors? Or are you asking about a yellow tire (automobile/robotics accessory)? Or did you mean “wire yellow” (since wires are color-coded, like yellow for signal)? 👉 If you are talking about robotic wheels (yellow tire + black rubber), then usually: They are made of plastic hubs (yellow) with rubber tires (black). Common size: 65mm × 26mm (fits TT motors). Used in DIY robotic cars.