This is more of a question can you use green coolant in a 2006 Chevy Equinox because I did. When I went for an oil change they said I was using the wrong color coolant. I should be using orange because they said all GM cars can only use orange. They charged me for a radiator flush. Did I really need one or did they get over on me? My dad had a Chevy truck and he used the green. Please let me know and my SUV wasn't overheating either.
They got over on you.
You can utilize the red, orange, blue, green, purple, whatever color of coolant. The deal is, if you do use green instead of orange (Dexcool), you need to follow the change intervals for the green coolant (IIRC, it's usually 24k miles or 24 months ... depending on the brand, but I believe that's about nominal).
The alternate colored coolant will not harm your cooling system. You just cannot expect it to last as long as Dexcool (150k miles or 5 years - or something like that).
There are differences in the coolants, see the link (not the only one and there may be better) : http://www.elf.com/en/advice-corner/coolant-and-antifreeze-faqs/antifreeze-types.html
The choice is down to the metals that are used in the engine (aluminium, cast iron etc). Another link here : http://www.bestproducts.com/cars/parts/g1484/engine-coolant-antifreeze/
Mixing coolants can cause a "gel" to form which gives problems poor cooling etc.
We do not run water as coolant in road vehicles due to the corrosion problems it can cause to the internal water passageways of the engine, and also due to issues with expansion, if the water were to freeze it can crack the engine block itself. We use coolant additives with properties that mitigate the issues mentioned above - the coolant prevents corrosion and freezing. Typically coolants are not as efficient as plain water at taking heat away from the hot parts of the engine and loosing that heat in the radiator. Use the correct coolant for the application - such as a anti-corrosive anti-freeze product designed for aluminium engines if your engine has an aluminium block and you operate in an environment where frost protection is necessary. The colour of the coolant is not important unless you are mixing coolant - which you should never do since this can cause a reaction and a gel to form. A race car will run pure distilled water or an expensive "coolant" with high heat exchange properties better than that of water. corrosion and anti-freeze properties are not important in a race.