Diesel oil, some colors are green, some colors are red. What is the normal color?

Hello; At present, in addition to national standard oil, diesel oil on the market also includes fuel oil (marine diesel oil) and non-standard oil. Passenger cars should use national standard oil. From the appearance alone, you can see the blue fluorescence when you put the fuel oil into the oil drum. The color of non-standard oil is red, but it is black and sticky. The national standard oil is light in color: yellow, green and low in viscosity. Under normal circumstances, high-quality automotive diesel oil should be colorless, light yellow or light brown transparent liquid, slightly transparent and without turbidity, while the color is dark black and soy sauce color, which is a low-grade blended oil; Turbidity is that inferior oil is mixed with water or impurities.