Shell * * * has five colors of packaging barrels. In fact, packaging barrels of various colors represent different uses and grades, and are also used for vehicles of different grades. Specifically, the five colors of shells are gray, blue, yellow, red and white. The ash shell is divided into supernormal oil and HX8 oil, both of which are synthetic oils. Blue shell is semi-synthetic oil; The yellow shell is divided into HX6 and HX5, in which HX6 is semi-synthetic oil and HX5 is mineral oil; The red shell is HX3 and the white shell is HX2, both of which are mineral oil. Besides, there are different grades of shale oil. Heineken series include Heineken HX2, HX3, HX5, HX6, HX7 and HX8. Among them, Heineken and Pure Heineken rank 2 from low to high. Shell * * * has five colors of gray, cyan, yellow, red and white, corresponding to different grades of oil products. Among them, ash shell is divided into supernormal oil and HX8 oil, both of which are synthetic oils. Similarly, the blue shell is semi-synthetic oil, and the yellow shell is divided into HX6 and HX5, in which HX6 is semi-synthetic oil, HX5 is mineral oil, and both red shell HX3 and white shell HX2 are mineral oil.