PVC pipe, otherwise called polyvinyl chloride pipe, has a number of uses. It is used in homes for water pipes, sewer system pipes and even furniture. Regardless of the use, there are times when colored PVC pipe is preferred. There are a few color options for PVC pipe available on the market.
White is the most common PVC pipe color and is commonly seen in plumbing and irrigation. Though it is the most common color for these projects, it is not a requirement to use white PVC pipe for plumbing.
Grey is the original PVC pipe color. According to the PPFA website, an industrial grey was the earliest PVC pipe color and it is still common. Like white, grey PVC pipe is often used for plumbing.
Green PVC pipe is less common than other colors. While PVC pipe colors are not regulated for specific uses, green PVC pipes are often used specifically for sewage.
Blue PVC pipe is available for personal purchase and does not have a specific purpose -- it can be used for any PVC pipe need. Some manufacturers color their PVC pipe blue to make it stand out from competitors' products.
Yellow, or similar colors such as buff, are not used for any specific purpose. They are available for consumer purchase for any reason.