Use a white paper towel or similar and sponge up the leaking fluid. I've always used the orange OAT DexCool. Here is a helpful site for color ID:

https://www.valvoline.com/our-produc...engine-coolant


If the expansion tank was overfilled one can expect to see 'overflow' puddles. Check with the white towel again. Orange? This should only happen once if it's overflow. Should the 'low coolant' light come on again there is a very good chance a minor leak is about to appear as a major leak. Often the small leaks are blown toward the engine by the radiator fan(s) and evaporate. (thanks Don B.)

There are dye pack kits to locate leaks and they work great if you are willing to get under the car to check some of the hose connections or you have a good eye you may be able to catch a view of the leak from under the hood. Buying a simple pressure testing tool is a good way to find the leak.

I bought (should have borrowed) a MityVac MV4560 for around $45. It also tests the pressure/radiator caps of various sizes. I was advised to pump up the coolant pressure to 12-14psi and look for coolant leak. AT 8psi, Bam! Thermostat housing had a gooched gasket and started its steady and persistent leak. Getting the part was the biggest challenge as my supplier sent me a housing with a180F 'stat. Should be 190F. That was resolved with a few calls/emails and colorful language. Changed some hoses as long as I had the expansion tank out of the way.

The cooling system of these 4.2 L engines were apparently designed by an octopus. Just be patient and fix this as soon as possible. Calling for help on the side of the road is an option best not tested.