The main use of mono ethylene glycol antifreeze coolant is for car antifreeze. It is used in cells cooling the car, the plane, the bus and all automotives. The monoethylene glycol anti freeze, having a low freezing point mixed with water, is commonly used in air conditioning as glycol cooling works below freezing temperature of 0 °C. The ethyelene glycol lowers the freezing point of the water proportionally on mixture, as propylene glycol antifreeze mix also does.
Mono ethylene glycol colour can be blue antifreeze, green and colorless depending on additives.

Take a look at freezing points of aqueous monoethyelene glycol anti freeze mixture. Adding more than 70% of ethylene glycol cooler in the solution the freezing point gets higher: