Gas pumps can make any grade or type of gasoline any color they want, and there are no laws that require specific colors to be associated with different kinds of gas. However, there are some commonalities between gas stations. While it may vary from gas station to gas station, most of the time, when you see a green-handled gas pump, you can expect that it is a diesel pump. The green color is often used to indicate diesel fuel, but this is not always the case, and the colors can change depending on the corporation behind the gas station. Therefore, it is important to read the labels and make sure you are getting the fuel you need for your specific motor.