white smoke = water vapor
blue smoke = oil burning
black smoke = partially burnt fuel
Anyhow, I did another test. Antifreeze has a slightly greasy feel when rubbing it between your fingers, whereas water does not. Based on that, I'm pretty sure the water is not AF. But the quantity of it sure mislead me, as well as the thick yellow color, which looked greenish outside. Most times I've seen just a few drops, and it was clear, of water coming out a car's tailpipe. The yellow color may come from the gas, which is a year old, or whatever is on the inside of the new header pipes.
I'm sure glad I asked you guys first before pulling the heads or the engine! Thank you!