New car tires often feature colored lines—red, yellow, blue, or white—running along the tire tread. These markings aren't technical indicators visible to the driver. Instead, they are internal factory markings used during the manufacturing process. Tire manufacturers use these colors to identify materials, categorize batches, and control quality throughout production. These markings help track components and ensure consistency in tire construction. They allow workers to easily identify tires in various stages of assembly. Ultimately, these colored lines aid in efficient production and quality assurance within the tire factory, before reaching consumers in Vietnam.