My antifreeze light came on so I pulled into a gas

I I used the green ethyl glycol for a while until the coolant level kept dropping daily. No leaks on the engine, hoses or ground. Found out that there are plastic parts in the exhaust manifold and ethyl glycol eats them then the engine eats the ethyl glycol. R&R with original plastic parts $850. R&R aftermarket aluminum parts $975. Always always always use the RED coolant (Dexcool)

The Orange antifreeze called GM Dexi cool, (red to your husband LOL). It's ok you put the green antifreeze in. The difference is the Green antifreeze has a of 1 year or 30,000 miles and the Orange has a life expectancy of 5 years or 100,000 miles. Being your Lumina is 12 years old and if the Orange antifreeze has never been flushed out, most likely crystals have formed in the water jackets and passageways through out the cooling system. The crystals can be flushed out with Preston radiator flush, but will take a few flushes to ensure that most of the crystals are out. Once flushed out, replace the antifreeze with the GM Dexi cool 50/50 mix water/antifreeze. Too much water will freeze and can crack the engine block, radiator, or heater core. To much Antifreeze will gel up causing the coolant to flow slower and then the engine tends to over heat. Note, it's a good time to replace the thermostat and spend the extra money for the fail safe thermostat. Good luck and keep me posted, be glad to answer any more questions.