That's a fascinating and surprisingly practical question! The short answer is yes, the color of an urban trash can absolutely can affect its internal temperature when placed in the sun, and the principle behind it is basic physics we experience daily.
The key mechanism is solar radiation and albedo—a surface's ability to reflect sunlight. Dark colors, like black or dark green, have a low albedo. They absorb most wavelengths of visible light, converting that light energy into heat energy. A black trash can essentially acts like a solar collector, causing its plastic or metal surface to become significantly hotter. This heat then conducts through the material, raising the air temperature inside the bin.
Conversely, light colors, especially white, have a high albedo. They reflect a large portion of the solar spectrum. A white trash can reflects much of that incoming energy away, so its surface and interior remain notably cooler. Studies on materials show this temperature difference can be substantial, potentially 10-20°C (18-36°F) or more between a dark and light-colored object in direct summer sun.
This has real-world implications for urban waste management. A hotter bin can accelerate the decomposition of organic waste, potentially leading to stronger odors and faster bacterial growth. It might also increase the off-gassing of volatile compounds from plastics. In very hot climates, extreme internal heat could even pose a slight risk of melting certain plastics or, in rare cases, contributing to combustion of very specific, highly flammable materials. Therefore, choosing lighter-colored bins for sun-exposed areas is a simple, passive design strategy for better thermal management, potentially reducing maintenance issues and nuisances. So, while often overlooked, the humble trash can's color is a small but valid point in urban heat island and practical public works considerations.