That's an interesting question with a more thoughtful answer than you might expect! While you'll see variations locally, globally the most popular color for public outdoor trash bins is overwhelmingly green.
This isn't accidental. Green is universally associated with nature, cleanliness, and environmental responsibility. Psychologically, it signals "proceed" or "acceptable," making people more likely to use the bin properly. Municipalities choose it to create a subtle, positive link between disposing of waste and keeping the environment clean.
You'll also see specific color codes for different waste streams, especially in regions with strong recycling programs. Blue is commonly reserved for recyclables like paper and plastic, black or gray for general non-recyclable waste, and sometimes brown for organic or compostable materials. However, the standard general-purpose bin you find on street corners, in parks, and in plazas is most frequently green.
The reasons are practical too. Green is a neutral, non-offensive color that blends reasonably well with both urban concrete and natural park settings. It also shows less dirt and fading than lighter colors, making maintenance appear more manageable for city services.
So next time you're walking down a street in Tokyo, Paris, or New York, look around. The humble green bin is a small piece of global urban design, working to keep our shared spaces cleaner.