Bissell spot cleaners are designed to remove spots and stains from carpets and upholstery. There are two main types of Bissell spot cleaners: purple and orange. The main difference between purple and orange Bissell spot cleaners is the color of the solution tank. Purple Bissell spot cleaners use a dark blue solution, while orange Bissell spot cleaners use a light green solution. The color of the solution tank does not affect the cleaning performance of the machine. Another difference between purple and orange Bissell spot cleaners is that orange machines have a built-in heater, while purple machines do not. The built-in heater helps to improve the cleaning performance of the machine by making the solution more effective at breaking down spots and stains.