oxidation on copper

I had an issue with moisture getting into my electrical panel. I found a tiny bit of oxidation on the neutral wire that is terminated in the neutral lug. It appeared as green on the tips of the strands of the wire. There is no corrosion however where the lug screw meets the wire. I have not had any apparent problems with my electric otherwise. As for the moisture, I think I have rectified any possible causes by sealing the conduit entering the panel. Fixing the driploop on my weatherhead and I have also started running a dehumidifier in the summer months in case its a condensation issue. I did not call an electrician to reterminate the wire though. If I have someone out right away, I fear if I did not correct the problem then it would occur again. And if I had already had an electrician re-terminate that wire, then there would likely not be enough slack in the wire to do so a second time without replacement of the feeder. So my question, should I be concerned than there is a bit of green on my copper? If the moisture is removed, does the copper continue to oxidize? I was thinking the neutral outside is bare and green from the weatherhead all the way to the transformer but I know that's not the same as being inside my equipment. What do you think?