I know that an antioxidant can be used on aluminum but this is copper. Is this antioxidant or something else?
Is the wire in a conduit? It could be wire pulling lubricant. Most popular brands of wire pulling lubricant are yellow but that is what it looks like.
If you are talking about the small darkened area on the green conductor, that is shelac that they used to cover copper wire with before the insulation covering was installed. This was done to prevent the copper from oxidizing while it was being stored on large spools before the insulation was braided onto it. It is normal and does not cause any problems.
I’m not for sure, but I think he was talking about the “green” on the green conductor…
Kind of looks a little like the line on a weed whacker after a few minutes of work…
Is that the service panel?
It’s green toxic MOLD!!! Kill the deal! Kill the deal!
In all seriousness, I agree with what the others said…
I would not worry about that too much. I would however point your attention to the breaker with double taps on a breaker not designed for such…and my eyes may be messin with me but they look like two different sizes also.