All anti-freeze (that I know of) has corrosion inhibitors. They wear out over time. So it's not just the green stuff. Dissimilar metals is what makes corrosion, and they haven't figured out how to make engines, radiators, waterpumps, & everything else out of EXACTLY the same alloy. So you need corrosion inhibitors, but they get used up.

Just about all antifreeze is ethene glycol, but the corrosion inhibitors are all different. Some combinations are bad news. Like if you put orange dexcool in, than later add some green Prestone, or even genuine Honda, it gets worse. So if you aren't sure what's in there now, dump it all & rinse several times.

Different carmakers have different mixes, based on the particular combinations of wetted metal alloys. So what's best for a VW (G-48) or a M-B (G-05) might not be best for a Honda. Corrosion can be a very complicated & detailed thing...

I wouldn't run any of them 100%, unless it's already diluted in the bottle. Which makes it the same as using 50/50 (read the label). Plain water is a better coolant than antifreeze, but that doesn't give you ANY corrosion protection.

I've heard stories about orange DexCool attacking some plastic materials, but that's only after a couple years. If you change it every 2 years or less, its OK. Just don't belive the bottle where it says 'lifetime'...