Trash bags are available in different colors, but your preference may be a matter of personal taste. White bags are a common choice because they blend in with their surroundings. This may be a consideration if your trash bag peeks out over the top of your trash can. Black trash cans are another popular choice because their dark color hides the contents. Black trash bags can block ultraviolet rays, so they often don't smell as much as bags of other colors when left outside. They can be made with a higher percentage of recycled materials than other trash bags, so they're often the least expensive option. Rainbow bags can be a fun option that injects some personality into trash collection. Some people who separate their trash also like using a different color for each type of trash.