No standard has yet to emerge. Generally, we see red or blue as being most common for metal; green is used for yard waste and, sometimes, food. Blue is often used for glass and blue or yellow are common for paper. And, black is used, often, for non-recyclable trash.
As you can see, colors are not consistently applied! Coding seems to vary enormously by community and depends, often, on the initial purchase of the bins.
In any case, we have found that color-coordinating your bins is a great idea. Make it easy distinguish each type and, importantly, increase participation rates!
If you have a unique color scheme in mind and cannot find a recycle label or sign that aligns with your scheme, it is easy to customize any of our designs.