These colored hose clamps are usually used for pipelines such as beverages, beer brewing, and chemical liquids. 

They mainly play a role of identification. Different colored hose clamps represent different types of pipes, so that workers can know the hose clamps of each color. Represents what kind of liquid is in the tube. 

These colors are not designed because they look good, but because of demand. For example, the brewery used blue head hose clamp in the pre-fermentation stage, yellow head hose clamp in the main fermentation stage, and green head hose clamp in the post-fermentation stage. 

The buckets of yeast liquid added by workers are also divided into three colors of blue, yellow and green, so that workers can greatly reduce addition errors. 

Nowadays, British-style clamps used on more and more areas, people can choose whatever color they like.