That's a great question that touches on urban design, psychology, and practical sanitation. These days, the most common and popular color for general public waste bins in urban areas is a very dark green, often a forest or hunter green, or a deep grey/charcoal. However, the real story is in the *system* of colors, not just a single one.
The shift from a single bin to multi-bin systems for recycling and composting has driven a move toward color-coding for instant public recognition. While there's no single global standard, strong trends have emerged:
* General Waste: Dark green or dark grey remains the classic, neutral workhorse for non-recyclable trash. It's subdued, doesn't show dirt easily, and is psychologically associated with "disposal."
* Recycling (Mixed/Containers): Blue has become the near-universal champion for recycling bins worldwide. It signals cleanliness, responsibility, and the "blue planet," creating a strong mental link to recycling.
* Organic/Compost Waste: Green (often a brighter, lime, or grass green) is increasingly standard for compostable materials. It directly connects to nature, food, and growth.
* Paper/Cardboard: In some systems, especially in Europe, yellow or white is dedicated for paper products.
So, while dark green for general trash is still prevalent, the most *noticeable* and promoted colors in a modern cityscape are the blue and bright green bins for recycling and organics. This color strategy is a low-cost, high-impact tool. It reduces contamination in recycling streams, improves sorting at the source, and makes a city's waste management system more efficient and intuitive for residents and tourists alike. The popularity of a color is now less about aesthetics and more about its function within a clear, communicative public system.