That's an excellent question, as the durability of the paint is a major factor in how long your outdoor trash cans will continue to look good. The good news is that most modern outdoor trash cans are designed with longevity in mind.
The paint used is typically a high-quality, powder-coated finish. This process involves applying a dry powder electrostatically and then curing it under heat, creating a much harder and more durable layer than traditional liquid paint. This coating is specifically formulated to be fade-resistant and to withstand constant exposure to the elements, including harsh UV rays from the sun.
While no colored object is entirely immune to the sun's powerful effects, a high-quality powder-coated finish will resist fading for many years. You can expect the color to remain vibrant and the surface to resist chipping, peeling, and rusting for a significant portion of the trash can's lifespan. To maximize this durability, it's a good practice to occasionally clean your bins with mild soap and water to remove dirt and pollutants that can, over a very long time, interact with sunlight to degrade the finish slightly faster. So, while some very gradual fading over many, many years is possible, you can be confident that your can is built to keep its looks through seasons of sun and rain.